diff --git a/.travis.yml b/.travis.yml
index a972668c95..8a7f65e3d6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,7 @@ matrix:
     - os: linux
       dist: trusty
       sudo: required
-      go: 1.7.6
+      go: 1.7.x
       script:
         - sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install fuse
         - sudo modprobe fuse
@@ -18,7 +18,7 @@ matrix:
     - os: linux
       dist: trusty
       sudo: required
-      go: 1.8.3
+      go: 1.8.x
       script:
         - sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install fuse
         - sudo modprobe fuse
@@ -31,7 +31,7 @@ matrix:
     - os: linux
       dist: trusty
       sudo: required
-      go: 1.9.0
+      go: 1.9.x
       script:
         - sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install fuse
         - sudo modprobe fuse
@@ -41,7 +41,7 @@ matrix:
         - go run build/ci.go test -coverage -misspell
 
     - os: osx
-      go: 1.9.0
+      go: 1.9.x
       sudo: required
       script:
         - brew update
@@ -54,7 +54,7 @@ matrix:
     - os: linux
       dist: trusty
       sudo: required
-      go: 1.9.0
+      go: 1.9.x
       env:
         - ubuntu-ppa
         - azure-linux
@@ -93,7 +93,7 @@ matrix:
       sudo: required
       services:
         - docker
-      go: 1.9.0
+      go: 1.9.x
       env:
         - azure-linux-mips
       script:
@@ -150,7 +150,7 @@ matrix:
 
     # This builder does the OSX Azure, iOS CocoaPods and iOS Azure uploads
     - os: osx
-      go: 1.9.0
+      go: 1.9.x
       env:
         - azure-osx
         - azure-ios
@@ -176,7 +176,7 @@ matrix:
     - os: linux
       dist: trusty
       sudo: required
-      go: 1.9.0
+      go: 1.9.x
       env:
         - azure-purge
       script:
diff --git a/VERSION b/VERSION
index bd8bf882d0..943f9cbc4e 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.7.0
+1.7.1
diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
index 88fb3331e8..d6d16eb3f9 100644
--- a/accounts/abi/bind/backends/simulated.go
+++ b/accounts/abi/bind/backends/simulated.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"math/big"
 	"sync"
+	"time"
 
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
@@ -284,6 +285,22 @@ func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transa
 	return nil
 }
 
+// JumpTimeInSeconds adds skip seconds to the clock
+func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), b.database, 1, func(number int, block *core.BlockGen) {
+		for _, tx := range b.pendingBlock.Transactions() {
+			block.AddTx(tx)
+		}
+		block.OffsetTime(int64(adjustment.Seconds()))
+	})
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), state.NewDatabase(b.database))
+
+	return nil
+}
+
 // callmsg implements core.Message to allow passing it as a transaction simulator.
 type callmsg struct {
 	ethereum.CallMsg
diff --git a/accounts/abi/bind/bind.go b/accounts/abi/bind/bind.go
index 73e95e02a1..f587580884 100644
--- a/accounts/abi/bind/bind.go
+++ b/accounts/abi/bind/bind.go
@@ -122,7 +122,7 @@ func Bind(types []string, abis []string, bytecodes []string, pkg string, lang La
 	}
 	// For Go bindings pass the code through goimports to clean it up and double check
 	if lang == LangGo {
-		code, err := imports.Process("", buffer.Bytes(), nil)
+		code, err := imports.Process(".", buffer.Bytes(), nil)
 		if err != nil {
 			return "", fmt.Errorf("%v\n%s", err, buffer)
 		}
diff --git a/accounts/abi/bind/bind_test.go b/accounts/abi/bind/bind_test.go
index 8ea3eca415..43ed53b922 100644
--- a/accounts/abi/bind/bind_test.go
+++ b/accounts/abi/bind/bind_test.go
@@ -459,7 +459,7 @@ func TestBindings(t *testing.T) {
 	}
 	// Skip the test if the go-ethereum sources are symlinked (https://github.com/golang/go/issues/14845)
 	linkTestCode := fmt.Sprintf("package linktest\nfunc CheckSymlinks(){\nfmt.Println(backends.NewSimulatedBackend(nil))\n}")
-	linkTestDeps, err := imports.Process("", []byte(linkTestCode), nil)
+	linkTestDeps, err := imports.Process(os.TempDir(), []byte(linkTestCode), nil)
 	if err != nil {
 		t.Fatalf("failed check for goimports symlink bug: %v", err)
 	}
diff --git a/cmd/puppeth/module_ethstats.go b/cmd/puppeth/module_ethstats.go
index 5d3fa5fc03..6ce662f65f 100644
--- a/cmd/puppeth/module_ethstats.go
+++ b/cmd/puppeth/module_ethstats.go
@@ -42,7 +42,7 @@ RUN \
 WORKDIR /eth-netstats
 EXPOSE 3000
 
-RUN echo 'module.exports = {trusted: [{{.Trusted}}], banned: [{{.Banned}}]};' > lib/utils/config.js
+RUN echo 'module.exports = {trusted: [{{.Trusted}}], banned: [{{.Banned}}], reserved: ["yournode"]};' > lib/utils/config.js
 
 CMD ["npm", "start"]
 `
diff --git a/cmd/utils/cmd.go b/cmd/utils/cmd.go
index 17c258c6c8..23b10c2d74 100644
--- a/cmd/utils/cmd.go
+++ b/cmd/utils/cmd.go
@@ -164,7 +164,7 @@ func ImportChain(chain *core.BlockChain, fn string) error {
 
 func hasAllBlocks(chain *core.BlockChain, bs []*types.Block) bool {
 	for _, b := range bs {
-		if !chain.HasBlock(b.Hash()) {
+		if !chain.HasBlock(b.Hash(), b.NumberU64()) {
 			return false
 		}
 	}
diff --git a/common/types.go b/common/types.go
index eaf8352fbc..d31bbf741b 100644
--- a/common/types.go
+++ b/common/types.go
@@ -88,7 +88,7 @@ func (h Hash) MarshalText() ([]byte, error) {
 	return hexutil.Bytes(h[:]).MarshalText()
 }
 
-// Sets the hash to the value of b. If b is larger than len(h) it will panic
+// Sets the hash to the value of b. If b is larger than len(h), 'b' will be cropped (from the left).
 func (h *Hash) SetBytes(b []byte) {
 	if len(b) > len(h) {
 		b = b[len(b)-HashLength:]
@@ -97,7 +97,7 @@ func (h *Hash) SetBytes(b []byte) {
 	copy(h[HashLength-len(b):], b)
 }
 
-// Set string `s` to h. If s is larger than len(h) it will panic
+// Set string `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
 func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }
 
 // Sets h to other
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index b714204458..6a19d449f3 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -36,9 +36,9 @@ import (
 
 // Ethash proof-of-work protocol constants.
 var (
-	frontierBlockReward   *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
-	metropolisBlockReward *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Metropolis
-	maxUncles                      = 2                 // Maximum number of uncles allowed in a single block
+	frontierBlockReward  *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
+	byzantiumBlockReward *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
+	maxUncles                     = 2                 // Maximum number of uncles allowed in a single block
 )
 
 // Various error messages to mark blocks invalid. These should be private to
@@ -290,8 +290,8 @@ func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *
 func CalcDifficulty(config *params.ChainConfig, time uint64, parent *types.Header) *big.Int {
 	next := new(big.Int).Add(parent.Number, big1)
 	switch {
-	case config.IsMetropolis(next):
-		return calcDifficultyMetropolis(time, parent)
+	case config.IsByzantium(next):
+		return calcDifficultyByzantium(time, parent)
 	case config.IsHomestead(next):
 		return calcDifficultyHomestead(time, parent)
 	default:
@@ -310,10 +310,10 @@ var (
 	big2999999    = big.NewInt(2999999)
 )
 
-// calcDifficultyMetropolis is the difficulty adjustment algorithm. It returns
+// calcDifficultyByzantium is the difficulty adjustment algorithm. It returns
 // the difficulty that a new block should have when created at time given the
-// parent block's time and difficulty. The calculation uses the Metropolis rules.
-func calcDifficultyMetropolis(time uint64, parent *types.Header) *big.Int {
+// parent block's time and difficulty. The calculation uses the Byzantium rules.
+func calcDifficultyByzantium(time uint64, parent *types.Header) *big.Int {
 	// https://github.com/ethereum/EIPs/issues/100.
 	// algorithm:
 	// diff = (parent_diff +
@@ -530,8 +530,8 @@ var (
 func AccumulateRewards(config *params.ChainConfig, state *state.StateDB, header *types.Header, uncles []*types.Header) {
 	// Select the correct block reward based on chain progression
 	blockReward := frontierBlockReward
-	if config.IsMetropolis(header.Number) {
-		blockReward = metropolisBlockReward
+	if config.IsByzantium(header.Number) {
+		blockReward = byzantiumBlockReward
 	}
 	// Accumulate the rewards for the miner and any included uncles
 	reward := new(big.Int).Set(blockReward)
diff --git a/containers/docker/master-alpine/Dockerfile b/containers/docker/master-alpine/Dockerfile
index b2467f1a78..44402361d7 100644
--- a/containers/docker/master-alpine/Dockerfile
+++ b/containers/docker/master-alpine/Dockerfile
@@ -2,7 +2,7 @@ FROM alpine:3.5
 
 RUN \
   apk add --update go git make gcc musl-dev linux-headers ca-certificates && \
-  git clone --depth 1 --branch release/1.6 https://github.com/ethereum/go-ethereum && \
+  git clone --depth 1 --branch release/1.7 https://github.com/ethereum/go-ethereum && \
   (cd go-ethereum && make geth) && \
   cp go-ethereum/build/bin/geth /geth && \
   apk del go git make gcc musl-dev linux-headers && \
diff --git a/containers/docker/master-ubuntu/Dockerfile b/containers/docker/master-ubuntu/Dockerfile
index 877ae94e99..cc4fad10c4 100644
--- a/containers/docker/master-ubuntu/Dockerfile
+++ b/containers/docker/master-ubuntu/Dockerfile
@@ -3,7 +3,7 @@ FROM ubuntu:xenial
 RUN \
   apt-get update && apt-get upgrade -q -y && \
   apt-get install -y --no-install-recommends golang git make gcc libc-dev ca-certificates && \
-  git clone --depth 1 --branch release/1.5 https://github.com/ethereum/go-ethereum && \
+  git clone --depth 1 --branch release/1.7 https://github.com/ethereum/go-ethereum && \
   (cd go-ethereum && make geth) && \
   cp go-ethereum/build/bin/geth /geth && \
   apt-get remove -y golang git make gcc libc-dev && apt autoremove -y && apt-get clean && \
diff --git a/contracts/chequebook/cheque_test.go b/contracts/chequebook/cheque_test.go
index 5f6a54a1c1..b7555d0815 100644
--- a/contracts/chequebook/cheque_test.go
+++ b/contracts/chequebook/cheque_test.go
@@ -232,8 +232,8 @@ func TestDeposit(t *testing.T) {
 	balance := new(big.Int).SetUint64(42)
 	chbook.Deposit(balance)
 	backend.Commit()
-	if chbook.balance.Cmp(balance) != 0 {
-		t.Fatalf("expected balance %v, got %v", balance, chbook.balance)
+	if chbook.Balance().Cmp(balance) != 0 {
+		t.Fatalf("expected balance %v, got %v", balance, chbook.Balance())
 	}
 
 	amount := common.Big1
@@ -243,8 +243,8 @@ func TestDeposit(t *testing.T) {
 	}
 	backend.Commit()
 	exp := new(big.Int).SetUint64(41)
-	if chbook.balance.Cmp(exp) != 0 {
-		t.Fatalf("expected balance %v, got %v", exp, chbook.balance)
+	if chbook.Balance().Cmp(exp) != 0 {
+		t.Fatalf("expected balance %v, got %v", exp, chbook.Balance())
 	}
 
 	// autodeposit on each issue
@@ -259,8 +259,8 @@ func TestDeposit(t *testing.T) {
 		t.Fatalf("expected no error, got %v", err)
 	}
 	backend.Commit()
-	if chbook.balance.Cmp(balance) != 0 {
-		t.Fatalf("expected balance %v, got %v", balance, chbook.balance)
+	if chbook.Balance().Cmp(balance) != 0 {
+		t.Fatalf("expected balance %v, got %v", balance, chbook.Balance())
 	}
 
 	// autodeposit off
@@ -277,11 +277,11 @@ func TestDeposit(t *testing.T) {
 	backend.Commit()
 
 	exp = new(big.Int).SetUint64(40)
-	if chbook.balance.Cmp(exp) != 0 {
-		t.Fatalf("expected balance %v, got %v", exp, chbook.balance)
+	if chbook.Balance().Cmp(exp) != 0 {
+		t.Fatalf("expected balance %v, got %v", exp, chbook.Balance())
 	}
 
-	// autodeposit every 10ms if new cheque issued
+	// autodeposit every 30ms if new cheque issued
 	interval := 30 * time.Millisecond
 	chbook.AutoDeposit(interval, common.Big1, balance)
 	_, err = chbook.Issue(addr1, amount)
@@ -296,14 +296,14 @@ func TestDeposit(t *testing.T) {
 	backend.Commit()
 
 	exp = new(big.Int).SetUint64(38)
-	if chbook.balance.Cmp(exp) != 0 {
-		t.Fatalf("expected balance %v, got %v", exp, chbook.balance)
+	if chbook.Balance().Cmp(exp) != 0 {
+		t.Fatalf("expected balance %v, got %v", exp, chbook.Balance())
 	}
 
 	time.Sleep(3 * interval)
 	backend.Commit()
-	if chbook.balance.Cmp(balance) != 0 {
-		t.Fatalf("expected balance %v, got %v", balance, chbook.balance)
+	if chbook.Balance().Cmp(balance) != 0 {
+		t.Fatalf("expected balance %v, got %v", balance, chbook.Balance())
 	}
 
 	exp = new(big.Int).SetUint64(40)
@@ -319,8 +319,8 @@ func TestDeposit(t *testing.T) {
 	}
 	time.Sleep(3 * interval)
 	backend.Commit()
-	if chbook.balance.Cmp(exp) != 0 {
-		t.Fatalf("expected balance %v, got %v", exp, chbook.balance)
+	if chbook.Balance().Cmp(exp) != 0 {
+		t.Fatalf("expected balance %v, got %v", exp, chbook.Balance())
 	}
 
 	_, err = chbook.Issue(addr1, amount)
@@ -330,8 +330,8 @@ func TestDeposit(t *testing.T) {
 	time.Sleep(1 * interval)
 	backend.Commit()
 
-	if chbook.balance.Cmp(balance) != 0 {
-		t.Fatalf("expected balance %v, got %v", balance, chbook.balance)
+	if chbook.Balance().Cmp(balance) != 0 {
+		t.Fatalf("expected balance %v, got %v", balance, chbook.Balance())
 	}
 
 	chbook.AutoDeposit(1*interval, common.Big0, balance)
@@ -352,8 +352,8 @@ func TestDeposit(t *testing.T) {
 	backend.Commit()
 
 	exp = new(big.Int).SetUint64(39)
-	if chbook.balance.Cmp(exp) != 0 {
-		t.Fatalf("expected balance %v, got %v", exp, chbook.balance)
+	if chbook.Balance().Cmp(exp) != 0 {
+		t.Fatalf("expected balance %v, got %v", exp, chbook.Balance())
 	}
 
 }
diff --git a/core/asm/lexer.go b/core/asm/lexer.go
index d784e5d504..a34b2cbd8f 100644
--- a/core/asm/lexer.go
+++ b/core/asm/lexer.go
@@ -145,7 +145,7 @@ func (l *lexer) ignore() {
 
 // Accepts checks whether the given input matches the next rune
 func (l *lexer) accept(valid string) bool {
-	if strings.IndexRune(valid, l.next()) >= 0 {
+	if strings.ContainsRune(valid, l.next()) {
 		return true
 	}
 
@@ -157,7 +157,7 @@ func (l *lexer) accept(valid string) bool {
 // acceptRun will continue to advance the seeker until valid
 // can no longer be met.
 func (l *lexer) acceptRun(valid string) {
-	for strings.IndexRune(valid, l.next()) >= 0 {
+	for strings.ContainsRune(valid, l.next()) {
 	}
 	l.backup()
 }
@@ -166,7 +166,7 @@ func (l *lexer) acceptRun(valid string) {
 // to advance the seeker until the rune has been found.
 func (l *lexer) acceptRunUntil(until rune) bool {
 	// Continues running until a rune is found
-	for i := l.next(); strings.IndexRune(string(until), i) == -1; i = l.next() {
+	for i := l.next(); !strings.ContainsRune(string(until), i); i = l.next() {
 		if i == 0 {
 			return false
 		}
diff --git a/core/blockchain.go b/core/blockchain.go
index d74b3520b1..235c1f3da2 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -23,7 +23,6 @@ import (
 	"io"
 	"math/big"
 	mrand "math/rand"
-	"runtime"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -515,10 +514,13 @@ func (bc *BlockChain) GetBodyRLP(hash common.Hash) rlp.RawValue {
 	return body
 }
 
-// HasBlock checks if a block is fully present in the database or not, caching
-// it if present.
-func (bc *BlockChain) HasBlock(hash common.Hash) bool {
-	return bc.GetBlockByHash(hash) != nil
+// HasBlock checks if a block is fully present in the database or not.
+func (bc *BlockChain) HasBlock(hash common.Hash, number uint64) bool {
+	if bc.blockCache.Contains(hash) {
+		return true
+	}
+	ok, _ := bc.chainDb.Has(blockBodyKey(hash, number))
+	return ok
 }
 
 // HasBlockAndState checks if a block and associated state trie is fully present
@@ -693,108 +695,73 @@ func SetReceiptsData(config *params.ChainConfig, block *types.Block, receipts ty
 
 // InsertReceiptChain attempts to complete an already existing header chain with
 // transaction and receipt data.
-// XXX should this be moved to the test?
 func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain []types.Receipts) (int, error) {
+	bc.wg.Add(1)
+	defer bc.wg.Done()
+
 	// Do a sanity check that the provided chain is actually ordered and linked
 	for i := 1; i < len(blockChain); i++ {
 		if blockChain[i].NumberU64() != blockChain[i-1].NumberU64()+1 || blockChain[i].ParentHash() != blockChain[i-1].Hash() {
-			// Chain broke ancestry, log a messge (programming error) and skip insertion
 			log.Error("Non contiguous receipt insert", "number", blockChain[i].Number(), "hash", blockChain[i].Hash(), "parent", blockChain[i].ParentHash(),
 				"prevnumber", blockChain[i-1].Number(), "prevhash", blockChain[i-1].Hash())
-
 			return 0, fmt.Errorf("non contiguous insert: item %d is #%d [%x…], item %d is #%d [%x…] (parent [%x…])", i-1, blockChain[i-1].NumberU64(),
 				blockChain[i-1].Hash().Bytes()[:4], i, blockChain[i].NumberU64(), blockChain[i].Hash().Bytes()[:4], blockChain[i].ParentHash().Bytes()[:4])
 		}
 	}
-	// Pre-checks passed, start the block body and receipt imports
-	bc.wg.Add(1)
-	defer bc.wg.Done()
 
-	// Collect some import statistics to report on
-	stats := struct{ processed, ignored int32 }{}
-	start := time.Now()
+	var (
+		stats = struct{ processed, ignored int32 }{}
+		start = time.Now()
+		bytes = 0
+		batch = bc.chainDb.NewBatch()
+	)
+	for i, block := range blockChain {
+		receipts := receiptChain[i]
+		// Short circuit insertion if shutting down or processing failed
+		if atomic.LoadInt32(&bc.procInterrupt) == 1 {
+			return 0, nil
+		}
+		// Short circuit if the owner header is unknown
+		if !bc.HasHeader(block.Hash(), block.NumberU64()) {
+			return i, fmt.Errorf("containing header #%d [%x…] unknown", block.Number(), block.Hash().Bytes()[:4])
+		}
+		// Skip if the entire data is already known
+		if bc.HasBlock(block.Hash(), block.NumberU64()) {
+			stats.ignored++
+			continue
+		}
+		// Compute all the non-consensus fields of the receipts
+		SetReceiptsData(bc.config, block, receipts)
+		// Write all the data out into the database
+		if err := WriteBody(batch, block.Hash(), block.NumberU64(), block.Body()); err != nil {
+			return i, fmt.Errorf("failed to write block body: %v", err)
+		}
+		if err := WriteBlockReceipts(batch, block.Hash(), block.NumberU64(), receipts); err != nil {
+			return i, fmt.Errorf("failed to write block receipts: %v", err)
+		}
+		if err := WriteTxLookupEntries(batch, block); err != nil {
+			return i, fmt.Errorf("failed to write lookup metadata: %v", err)
+		}
+		stats.processed++
 
-	// Create the block importing task queue and worker functions
-	tasks := make(chan int, len(blockChain))
-	for i := 0; i < len(blockChain) && i < len(receiptChain); i++ {
-		tasks <- i
-	}
-	close(tasks)
-
-	errs, failed := make([]error, len(tasks)), int32(0)
-	process := func(worker int) {
-		for index := range tasks {
-			block, receipts := blockChain[index], receiptChain[index]
-
-			// Short circuit insertion if shutting down or processing failed
-			if atomic.LoadInt32(&bc.procInterrupt) == 1 {
-				return
+		if batch.ValueSize() >= ethdb.IdealBatchSize {
+			if err := batch.Write(); err != nil {
+				return 0, err
 			}
-			if atomic.LoadInt32(&failed) > 0 {
-				return
-			}
-			// Short circuit if the owner header is unknown
-			if !bc.HasHeader(block.Hash()) {
-				errs[index] = fmt.Errorf("containing header #%d [%x…] unknown", block.Number(), block.Hash().Bytes()[:4])
-				atomic.AddInt32(&failed, 1)
-				return
-			}
-			// Skip if the entire data is already known
-			if bc.HasBlock(block.Hash()) {
-				atomic.AddInt32(&stats.ignored, 1)
-				continue
-			}
-			// Compute all the non-consensus fields of the receipts
-			SetReceiptsData(bc.config, block, receipts)
-			// Write all the data out into the database
-			if err := WriteBody(bc.chainDb, block.Hash(), block.NumberU64(), block.Body()); err != nil {
-				errs[index] = fmt.Errorf("failed to write block body: %v", err)
-				atomic.AddInt32(&failed, 1)
-				log.Crit("Failed to write block body", "err", err)
-				return
-			}
-			if err := WriteBlockReceipts(bc.chainDb, block.Hash(), block.NumberU64(), receipts); err != nil {
-				errs[index] = fmt.Errorf("failed to write block receipts: %v", err)
-				atomic.AddInt32(&failed, 1)
-				log.Crit("Failed to write block receipts", "err", err)
-				return
-			}
-			if err := WriteTxLookupEntries(bc.chainDb, block); err != nil {
-				errs[index] = fmt.Errorf("failed to write lookup metadata: %v", err)
-				atomic.AddInt32(&failed, 1)
-				log.Crit("Failed to write lookup metadata", "err", err)
-				return
-			}
-			atomic.AddInt32(&stats.processed, 1)
+			bytes += batch.ValueSize()
+			batch = bc.chainDb.NewBatch()
 		}
 	}
-	// Start as many worker threads as goroutines allowed
-	pending := new(sync.WaitGroup)
-	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
-		pending.Add(1)
-		go func(id int) {
-			defer pending.Done()
-			process(id)
-		}(i)
-	}
-	pending.Wait()
-
-	// If anything failed, report
-	if failed > 0 {
-		for i, err := range errs {
-			if err != nil {
-				return i, err
-			}
+	if batch.ValueSize() > 0 {
+		bytes += batch.ValueSize()
+		if err := batch.Write(); err != nil {
+			return 0, err
 		}
 	}
-	if atomic.LoadInt32(&bc.procInterrupt) == 1 {
-		log.Debug("Premature abort during receipts processing")
-		return 0, nil
-	}
+
 	// Update the head fast sync block if better
 	bc.mu.Lock()
-
-	head := blockChain[len(errs)-1]
+	head := blockChain[len(blockChain)-1]
 	if td := bc.GetTd(head.Hash(), head.NumberU64()); td != nil { // Rewind may have occurred, skip in that case
 		if bc.GetTd(bc.currentFastBlock.Hash(), bc.currentFastBlock.NumberU64()).Cmp(td) < 0 {
 			if err := WriteHeadFastBlockHash(bc.chainDb, head.Hash()); err != nil {
@@ -805,16 +772,18 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 	}
 	bc.mu.Unlock()
 
-	// Report some public statistics so the user has a clue what's going on
-	last := blockChain[len(blockChain)-1]
-	log.Info("Imported new block receipts", "count", stats.processed, "elapsed", common.PrettyDuration(time.Since(start)),
-		"number", last.Number(), "hash", last.Hash(), "ignored", stats.ignored)
-
+	log.Info("Imported new block receipts",
+		"count", stats.processed,
+		"elapsed", common.PrettyDuration(time.Since(start)),
+		"bytes", bytes,
+		"number", head.Number(),
+		"hash", head.Hash(),
+		"ignored", stats.ignored)
 	return 0, nil
 }
 
 // WriteBlock writes the block to the chain.
-func (bc *BlockChain) WriteBlock(block *types.Block) (status WriteStatus, err error) {
+func (bc *BlockChain) WriteBlockAndState(block *types.Block, receipts []*types.Receipt, state *state.StateDB) (status WriteStatus, err error) {
 	bc.wg.Add(1)
 	defer bc.wg.Done()
 
@@ -827,7 +796,7 @@ func (bc *BlockChain) WriteBlock(block *types.Block) (status WriteStatus, err er
 	bc.mu.Lock()
 	defer bc.mu.Unlock()
 
-	if bc.HasBlock(block.Hash()) {
+	if bc.HasBlock(block.Hash(), block.NumberU64()) {
 		log.Trace("Block existed", "hash", block.Hash())
 		return
 	}
@@ -837,10 +806,18 @@ func (bc *BlockChain) WriteBlock(block *types.Block) (status WriteStatus, err er
 
 	// Irrelevant of the canonical status, write the block itself to the database
 	if err := bc.hc.WriteTd(block.Hash(), block.NumberU64(), externTd); err != nil {
-		log.Crit("Failed to write block total difficulty", "err", err)
+		return NonStatTy, err
 	}
-	if err := WriteBlock(bc.chainDb, block); err != nil {
-		log.Crit("Failed to write block contents", "err", err)
+	// Write other block data using a batch.
+	batch := bc.chainDb.NewBatch()
+	if err := WriteBlock(batch, block); err != nil {
+		return NonStatTy, err
+	}
+	if _, err := state.CommitTo(batch, bc.config.IsEIP158(block.Number())); err != nil {
+		return NonStatTy, err
+	}
+	if err := WriteBlockReceipts(batch, block.Hash(), block.NumberU64(), receipts); err != nil {
+		return NonStatTy, err
 	}
 
 	// If the total difficulty is higher than our known, add it to the canonical chain
@@ -853,20 +830,46 @@ func (bc *BlockChain) WriteBlock(block *types.Block) (status WriteStatus, err er
 				return NonStatTy, err
 			}
 		}
-		bc.insert(block) // Insert the block as the new head of the chain
+		// Write the positional metadata for transaction and receipt lookups
+		if err := WriteTxLookupEntries(batch, block); err != nil {
+			return NonStatTy, err
+		}
+		// Write hash preimages
+		if err := WritePreimages(bc.chainDb, block.NumberU64(), state.Preimages()); err != nil {
+			return NonStatTy, err
+		}
 		status = CanonStatTy
 	} else {
 		status = SideStatTy
 	}
+	if err := batch.Write(); err != nil {
+		return NonStatTy, err
+	}
 
+	// Set new head.
+	if status == CanonStatTy {
+		bc.insert(block)
+	}
 	bc.futureBlocks.Remove(block.Hash())
-
-	return
+	return status, nil
 }
 
-// InsertChain will attempt to insert the given chain in to the canonical chain or, otherwise, create a fork. If an error is returned
-// it will return the index number of the failing block as well an error describing what went wrong (for possible errors see core/errors.go).
+// InsertChain attempts to insert the given batch of blocks in to the canonical
+// chain or, otherwise, create a fork. If an error is returned it will return
+// the index number of the failing block as well an error describing what went
+// wrong.
+//
+// After insertion is done, all accumulated events will be fired.
 func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
+	n, events, logs, err := bc.insertChain(chain)
+	bc.PostChainEvents(events, logs)
+	return n, err
+}
+
+// insertChain will execute the actual chain insertion and event aggregation. The
+// only reason this method exists as a separate one is to make locking cleaner
+// with deferred statements.
+func (bc *BlockChain) insertChain(chain types.Blocks) (int, []interface{}, []*types.Log, error) {
 	// Do a sanity check that the provided chain is actually ordered and linked
 	for i := 1; i < len(chain); i++ {
 		if chain[i].NumberU64() != chain[i-1].NumberU64()+1 || chain[i].ParentHash() != chain[i-1].Hash() {
@@ -874,7 +877,7 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 			log.Error("Non contiguous block insert", "number", chain[i].Number(), "hash", chain[i].Hash(),
 				"parent", chain[i].ParentHash(), "prevnumber", chain[i-1].Number(), "prevhash", chain[i-1].Hash())
 
-			return 0, fmt.Errorf("non contiguous insert: item %d is #%d [%x…], item %d is #%d [%x…] (parent [%x…])", i-1, chain[i-1].NumberU64(),
+			return 0, nil, nil, fmt.Errorf("non contiguous insert: item %d is #%d [%x…], item %d is #%d [%x…] (parent [%x…])", i-1, chain[i-1].NumberU64(),
 				chain[i-1].Hash().Bytes()[:4], i, chain[i].NumberU64(), chain[i].Hash().Bytes()[:4], chain[i].ParentHash().Bytes()[:4])
 		}
 	}
@@ -891,6 +894,7 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 	var (
 		stats         = insertStats{startTime: mclock.Now()}
 		events        = make([]interface{}, 0, len(chain))
+		lastCanon     *types.Block
 		coalescedLogs []*types.Log
 	)
 	// Start the parallel header verifier
@@ -914,7 +918,7 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 		// If the header is a banned one, straight out abort
 		if BadHashes[block.Hash()] {
 			bc.reportBlock(block, nil, ErrBlacklistedHash)
-			return i, ErrBlacklistedHash
+			return i, events, coalescedLogs, ErrBlacklistedHash
 		}
 		// Wait for the block's verification to complete
 		bstart := time.Now()
@@ -935,7 +939,7 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 				// if given.
 				max := big.NewInt(time.Now().Unix() + maxTimeFutureBlocks)
 				if block.Time().Cmp(max) > 0 {
-					return i, fmt.Errorf("future block: %v > %v", block.Time(), max)
+					return i, events, coalescedLogs, fmt.Errorf("future block: %v > %v", block.Time(), max)
 				}
 				bc.futureBlocks.Add(block.Hash(), block)
 				stats.queued++
@@ -949,7 +953,7 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 			}
 
 			bc.reportBlock(block, nil, err)
-			return i, err
+			return i, events, coalescedLogs, err
 		}
 		// Create a new statedb using the parent block and report an
 		// error if it fails.
@@ -961,60 +965,35 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 		}
 		state, err := state.New(parent.Root(), bc.stateCache)
 		if err != nil {
-			return i, err
+			return i, events, coalescedLogs, err
 		}
 		// Process block using the parent state as reference point.
 		receipts, logs, usedGas, err := bc.processor.Process(block, state, bc.vmConfig)
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
-			return i, err
+			return i, events, coalescedLogs, err
 		}
 		// Validate the state using the default validator
 		err = bc.Validator().ValidateState(block, parent, state, receipts, usedGas)
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
-			return i, err
+			return i, events, coalescedLogs, err
 		}
-		// Write state changes to database
-		if _, err = state.CommitTo(bc.chainDb, bc.config.IsEIP158(block.Number())); err != nil {
-			return i, err
-		}
-
-		// coalesce logs for later processing
-		coalescedLogs = append(coalescedLogs, logs...)
-
-		if err = WriteBlockReceipts(bc.chainDb, block.Hash(), block.NumberU64(), receipts); err != nil {
-			return i, err
-		}
-
-		// write the block to the chain and get the status
-		status, err := bc.WriteBlock(block)
+		// Write the block to the chain and get the status.
+		status, err := bc.WriteBlockAndState(block, receipts, state)
 		if err != nil {
-			return i, err
+			return i, events, coalescedLogs, err
 		}
-
 		switch status {
 		case CanonStatTy:
 			log.Debug("Inserted new block", "number", block.Number(), "hash", block.Hash(), "uncles", len(block.Uncles()),
 				"txs", len(block.Transactions()), "gas", block.GasUsed(), "elapsed", common.PrettyDuration(time.Since(bstart)))
 
+			coalescedLogs = append(coalescedLogs, logs...)
 			blockInsertTimer.UpdateSince(bstart)
 			events = append(events, ChainEvent{block, block.Hash(), logs})
-			// We need some control over the mining operation. Acquiring locks and waiting
-			// for the miner to create new block takes too long and in most cases isn't
-			// even necessary.
-			if bc.LastBlockHash() == block.Hash() {
-				events = append(events, ChainHeadEvent{block})
-			}
+			lastCanon = block
 
-			// Write the positional metadata for transaction and receipt lookups
-			if err := WriteTxLookupEntries(bc.chainDb, block); err != nil {
-				return i, err
-			}
-			// Write hash preimages
-			if err := WritePreimages(bc.chainDb, block.NumberU64(), state.Preimages()); err != nil {
-				return i, err
-			}
 		case SideStatTy:
 			log.Debug("Inserted forked block", "number", block.Number(), "hash", block.Hash(), "diff", block.Difficulty(), "elapsed",
 				common.PrettyDuration(time.Since(bstart)), "txs", len(block.Transactions()), "gas", block.GasUsed(), "uncles", len(block.Uncles()))
@@ -1026,9 +1005,11 @@ func (bc *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 		stats.usedGas += usedGas.Uint64()
 		stats.report(chain, i)
 	}
-	go bc.PostChainEvents(events, coalescedLogs)
-
-	return 0, nil
+	// Append a single chain head event if we've progressed the chain
+	if lastCanon != nil && bc.LastBlockHash() == lastCanon.Hash() {
+		events = append(events, ChainHeadEvent{lastCanon})
+	}
+	return 0, events, coalescedLogs, nil
 }
 
 // insertStats tracks and reports on block insertion.
@@ -1357,8 +1338,8 @@ func (bc *BlockChain) GetHeaderByHash(hash common.Hash) *types.Header {
 
 // HasHeader checks if a block header is present in the database or not, caching
 // it if present.
-func (bc *BlockChain) HasHeader(hash common.Hash) bool {
-	return bc.hc.HasHeader(hash)
+func (bc *BlockChain) HasHeader(hash common.Hash, number uint64) bool {
+	return bc.hc.HasHeader(hash, number)
 }
 
 // GetBlockHashesFromHash retrieves a number of block hashes starting at a given
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index 470974a0a7..cb1df8d4b0 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -928,14 +928,14 @@ func TestReorgSideEvent(t *testing.T) {
 	replacementBlocks, _ := GenerateChain(gspec.Config, genesis, db, 4, func(i int, gen *BlockGen) {
 		tx, err := types.SignTx(types.NewContractCreation(gen.TxNonce(addr1), new(big.Int), big.NewInt(1000000), new(big.Int), nil), signer, key1)
 		if i == 2 {
-			gen.OffsetTime(-1)
+			gen.OffsetTime(-9)
 		}
 		if err != nil {
 			t.Fatalf("failed to create tx: %v", err)
 		}
 		gen.AddTx(tx)
 	})
-	chainSideCh := make(chan ChainSideEvent)
+	chainSideCh := make(chan ChainSideEvent, 64)
 	blockchain.SubscribeChainSideEvent(chainSideCh)
 	if _, err := blockchain.InsertChain(replacementBlocks); err != nil {
 		t.Fatalf("failed to insert chain: %v", err)
diff --git a/core/dao.go b/core/dao.go
deleted file mode 100644
index ff42a0e9d3..0000000000
--- a/core/dao.go
+++ /dev/null
@@ -1,75 +0,0 @@
-// Copyright 2016 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package core
-
-import (
-	"bytes"
-	"fmt"
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/core/state"
-	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/params"
-)
-
-// ValidateDAOHeaderExtraData validates the extra-data field of a block header to
-// ensure it conforms to DAO hard-fork rules.
-//
-// DAO hard-fork extension to the header validity:
-//   a) if the node is no-fork, do not accept blocks in the [fork, fork+10) range
-//      with the fork specific extra-data set
-//   b) if the node is pro-fork, require blocks in the specific range to have the
-//      unique extra-data set.
-func ValidateDAOHeaderExtraData(config *params.ChainConfig, header *types.Header) error {
-	// Short circuit validation if the node doesn't care about the DAO fork
-	if config.DAOForkBlock == nil {
-		return nil
-	}
-	// Make sure the block is within the fork's modified extra-data range
-	limit := new(big.Int).Add(config.DAOForkBlock, params.DAOForkExtraRange)
-	if header.Number.Cmp(config.DAOForkBlock) < 0 || header.Number.Cmp(limit) >= 0 {
-		return nil
-	}
-	// Depending whether we support or oppose the fork, validate the extra-data contents
-	if config.DAOForkSupport {
-		if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
-			return fmt.Errorf("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
-		}
-	} else {
-		if bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
-			return fmt.Errorf("DAO no-fork bad block extra-data: 0x%x", header.Extra)
-		}
-	}
-	// All ok, header has the same extra-data we expect
-	return nil
-}
-
-// ApplyDAOHardFork modifies the state database according to the DAO hard-fork
-// rules, transferring all balances of a set of DAO accounts to a single refund
-// contract.
-func ApplyDAOHardFork(statedb *state.StateDB) {
-	// Retrieve the contract to refund balances into
-	if !statedb.Exist(params.DAORefundContract) {
-		statedb.CreateAccount(params.DAORefundContract)
-	}
-
-	// Move every DAO account and extra-balance account funds into the refund contract
-	for _, addr := range params.DAODrainList() {
-		statedb.AddBalance(params.DAORefundContract, statedb.GetBalance(addr))
-		statedb.SetBalance(addr, new(big.Int))
-	}
-}
diff --git a/core/dao_test.go b/core/dao_test.go
index d6e11d78ae..b9898ff7c8 100644
--- a/core/dao_test.go
+++ b/core/dao_test.go
@@ -40,14 +40,22 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	// Create the concurrent, conflicting two nodes
 	proDb, _ := ethdb.NewMemDatabase()
 	gspec.MustCommit(proDb)
-	proConf := &params.ChainConfig{HomesteadBlock: big.NewInt(0), DAOForkBlock: forkBlock, DAOForkSupport: true}
-	proBc, _ := NewBlockChain(proDb, proConf, ethash.NewFaker(), vm.Config{})
+
+	proConf := *params.TestChainConfig
+	proConf.DAOForkBlock = forkBlock
+	proConf.DAOForkSupport = true
+
+	proBc, _ := NewBlockChain(proDb, &proConf, ethash.NewFaker(), vm.Config{})
 	defer proBc.Stop()
 
 	conDb, _ := ethdb.NewMemDatabase()
 	gspec.MustCommit(conDb)
-	conConf := &params.ChainConfig{HomesteadBlock: big.NewInt(0), DAOForkBlock: forkBlock, DAOForkSupport: false}
-	conBc, _ := NewBlockChain(conDb, conConf, ethash.NewFaker(), vm.Config{})
+
+	conConf := *params.TestChainConfig
+	conConf.DAOForkBlock = forkBlock
+	conConf.DAOForkSupport = false
+
+	conBc, _ := NewBlockChain(conDb, &conConf, ethash.NewFaker(), vm.Config{})
 	defer conBc.Stop()
 
 	if _, err := proBc.InsertChain(prefix); err != nil {
@@ -61,7 +69,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		// Create a pro-fork block, and try to feed into the no-fork chain
 		db, _ = ethdb.NewMemDatabase()
 		gspec.MustCommit(db)
-		bc, _ := NewBlockChain(db, conConf, ethash.NewFaker(), vm.Config{})
+		bc, _ := NewBlockChain(db, &conConf, ethash.NewFaker(), vm.Config{})
 		defer bc.Stop()
 
 		blocks := conBc.GetBlocksFromHash(conBc.CurrentBlock().Hash(), int(conBc.CurrentBlock().NumberU64()))
@@ -71,19 +79,19 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		if _, err := bc.InsertChain(blocks); err != nil {
 			t.Fatalf("failed to import contra-fork chain for expansion: %v", err)
 		}
-		blocks, _ = GenerateChain(proConf, conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&proConf, conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
 		if _, err := conBc.InsertChain(blocks); err == nil {
 			t.Fatalf("contra-fork chain accepted pro-fork block: %v", blocks[0])
 		}
 		// Create a proper no-fork block for the contra-forker
-		blocks, _ = GenerateChain(conConf, conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&conConf, conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
 		if _, err := conBc.InsertChain(blocks); err != nil {
 			t.Fatalf("contra-fork chain didn't accepted no-fork block: %v", err)
 		}
 		// Create a no-fork block, and try to feed into the pro-fork chain
 		db, _ = ethdb.NewMemDatabase()
 		gspec.MustCommit(db)
-		bc, _ = NewBlockChain(db, proConf, ethash.NewFaker(), vm.Config{})
+		bc, _ = NewBlockChain(db, &proConf, ethash.NewFaker(), vm.Config{})
 		defer bc.Stop()
 
 		blocks = proBc.GetBlocksFromHash(proBc.CurrentBlock().Hash(), int(proBc.CurrentBlock().NumberU64()))
@@ -93,12 +101,12 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 		if _, err := bc.InsertChain(blocks); err != nil {
 			t.Fatalf("failed to import pro-fork chain for expansion: %v", err)
 		}
-		blocks, _ = GenerateChain(conConf, proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&conConf, proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
 		if _, err := proBc.InsertChain(blocks); err == nil {
 			t.Fatalf("pro-fork chain accepted contra-fork block: %v", blocks[0])
 		}
 		// Create a proper pro-fork block for the pro-forker
-		blocks, _ = GenerateChain(proConf, proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+		blocks, _ = GenerateChain(&proConf, proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
 		if _, err := proBc.InsertChain(blocks); err != nil {
 			t.Fatalf("pro-fork chain didn't accepted pro-fork block: %v", err)
 		}
@@ -106,7 +114,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	// Verify that contra-forkers accept pro-fork extra-datas after forking finishes
 	db, _ = ethdb.NewMemDatabase()
 	gspec.MustCommit(db)
-	bc, _ := NewBlockChain(db, conConf, ethash.NewFaker(), vm.Config{})
+	bc, _ := NewBlockChain(db, &conConf, ethash.NewFaker(), vm.Config{})
 	defer bc.Stop()
 
 	blocks := conBc.GetBlocksFromHash(conBc.CurrentBlock().Hash(), int(conBc.CurrentBlock().NumberU64()))
@@ -116,14 +124,14 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	if _, err := bc.InsertChain(blocks); err != nil {
 		t.Fatalf("failed to import contra-fork chain for expansion: %v", err)
 	}
-	blocks, _ = GenerateChain(proConf, conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+	blocks, _ = GenerateChain(&proConf, conBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
 	if _, err := conBc.InsertChain(blocks); err != nil {
 		t.Fatalf("contra-fork chain didn't accept pro-fork block post-fork: %v", err)
 	}
 	// Verify that pro-forkers accept contra-fork extra-datas after forking finishes
 	db, _ = ethdb.NewMemDatabase()
 	gspec.MustCommit(db)
-	bc, _ = NewBlockChain(db, proConf, ethash.NewFaker(), vm.Config{})
+	bc, _ = NewBlockChain(db, &proConf, ethash.NewFaker(), vm.Config{})
 	defer bc.Stop()
 
 	blocks = proBc.GetBlocksFromHash(proBc.CurrentBlock().Hash(), int(proBc.CurrentBlock().NumberU64()))
@@ -133,7 +141,7 @@ func TestDAOForkRangeExtradata(t *testing.T) {
 	if _, err := bc.InsertChain(blocks); err != nil {
 		t.Fatalf("failed to import pro-fork chain for expansion: %v", err)
 	}
-	blocks, _ = GenerateChain(conConf, proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
+	blocks, _ = GenerateChain(&conConf, proBc.CurrentBlock(), db, 1, func(i int, gen *BlockGen) {})
 	if _, err := proBc.InsertChain(blocks); err != nil {
 		t.Fatalf("pro-fork chain didn't accept contra-fork block post-fork: %v", err)
 	}
diff --git a/core/database_util.go b/core/database_util.go
index 989071104e..1730a048e7 100644
--- a/core/database_util.go
+++ b/core/database_util.go
@@ -38,11 +38,6 @@ type DatabaseReader interface {
 	Get(key []byte) (value []byte, err error)
 }
 
-// DatabaseWriter wraps the Put method of a backing data store.
-type DatabaseWriter interface {
-	Put(key, value []byte) error
-}
-
 // DatabaseDeleter wraps the Delete method of a backing data store.
 type DatabaseDeleter interface {
 	Delete(key []byte) error
@@ -154,7 +149,7 @@ func GetHeadFastBlockHash(db DatabaseReader) common.Hash {
 // GetHeaderRLP retrieves a block header in its raw RLP database encoding, or nil
 // if the header's not found.
 func GetHeaderRLP(db DatabaseReader, hash common.Hash, number uint64) rlp.RawValue {
-	data, _ := db.Get(append(append(headerPrefix, encodeBlockNumber(number)...), hash.Bytes()...))
+	data, _ := db.Get(headerKey(hash, number))
 	return data
 }
 
@@ -175,10 +170,18 @@ func GetHeader(db DatabaseReader, hash common.Hash, number uint64) *types.Header
 
 // GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
 func GetBodyRLP(db DatabaseReader, hash common.Hash, number uint64) rlp.RawValue {
-	data, _ := db.Get(append(append(bodyPrefix, encodeBlockNumber(number)...), hash.Bytes()...))
+	data, _ := db.Get(blockBodyKey(hash, number))
 	return data
 }
 
+func headerKey(hash common.Hash, number uint64) []byte {
+	return append(append(headerPrefix, encodeBlockNumber(number)...), hash.Bytes()...)
+}
+
+func blockBodyKey(hash common.Hash, number uint64) []byte {
+	return append(append(bodyPrefix, encodeBlockNumber(number)...), hash.Bytes()...)
+}
+
 // GetBody retrieves the block body (transactons, uncles) corresponding to the
 // hash, nil if none found.
 func GetBody(db DatabaseReader, hash common.Hash, number uint64) *types.Body {
@@ -340,7 +343,7 @@ func GetBloomBits(db DatabaseReader, bit uint, section uint64, head common.Hash)
 }
 
 // WriteCanonicalHash stores the canonical hash for the given block number.
-func WriteCanonicalHash(db DatabaseWriter, hash common.Hash, number uint64) error {
+func WriteCanonicalHash(db ethdb.Putter, hash common.Hash, number uint64) error {
 	key := append(append(headerPrefix, encodeBlockNumber(number)...), numSuffix...)
 	if err := db.Put(key, hash.Bytes()); err != nil {
 		log.Crit("Failed to store number to hash mapping", "err", err)
@@ -349,7 +352,7 @@ func WriteCanonicalHash(db DatabaseWriter, hash common.Hash, number uint64) erro
 }
 
 // WriteHeadHeaderHash stores the head header's hash.
-func WriteHeadHeaderHash(db DatabaseWriter, hash common.Hash) error {
+func WriteHeadHeaderHash(db ethdb.Putter, hash common.Hash) error {
 	if err := db.Put(headHeaderKey, hash.Bytes()); err != nil {
 		log.Crit("Failed to store last header's hash", "err", err)
 	}
@@ -357,7 +360,7 @@ func WriteHeadHeaderHash(db DatabaseWriter, hash common.Hash) error {
 }
 
 // WriteHeadBlockHash stores the head block's hash.
-func WriteHeadBlockHash(db DatabaseWriter, hash common.Hash) error {
+func WriteHeadBlockHash(db ethdb.Putter, hash common.Hash) error {
 	if err := db.Put(headBlockKey, hash.Bytes()); err != nil {
 		log.Crit("Failed to store last block's hash", "err", err)
 	}
@@ -365,7 +368,7 @@ func WriteHeadBlockHash(db DatabaseWriter, hash common.Hash) error {
 }
 
 // WriteHeadFastBlockHash stores the fast head block's hash.
-func WriteHeadFastBlockHash(db DatabaseWriter, hash common.Hash) error {
+func WriteHeadFastBlockHash(db ethdb.Putter, hash common.Hash) error {
 	if err := db.Put(headFastKey, hash.Bytes()); err != nil {
 		log.Crit("Failed to store last fast block's hash", "err", err)
 	}
@@ -373,7 +376,7 @@ func WriteHeadFastBlockHash(db DatabaseWriter, hash common.Hash) error {
 }
 
 // WriteHeader serializes a block header into the database.
-func WriteHeader(db DatabaseWriter, header *types.Header) error {
+func WriteHeader(db ethdb.Putter, header *types.Header) error {
 	data, err := rlp.EncodeToBytes(header)
 	if err != nil {
 		return err
@@ -393,7 +396,7 @@ func WriteHeader(db DatabaseWriter, header *types.Header) error {
 }
 
 // WriteBody serializes the body of a block into the database.
-func WriteBody(db DatabaseWriter, hash common.Hash, number uint64, body *types.Body) error {
+func WriteBody(db ethdb.Putter, hash common.Hash, number uint64, body *types.Body) error {
 	data, err := rlp.EncodeToBytes(body)
 	if err != nil {
 		return err
@@ -402,7 +405,7 @@ func WriteBody(db DatabaseWriter, hash common.Hash, number uint64, body *types.B
 }
 
 // WriteBodyRLP writes a serialized body of a block into the database.
-func WriteBodyRLP(db DatabaseWriter, hash common.Hash, number uint64, rlp rlp.RawValue) error {
+func WriteBodyRLP(db ethdb.Putter, hash common.Hash, number uint64, rlp rlp.RawValue) error {
 	key := append(append(bodyPrefix, encodeBlockNumber(number)...), hash.Bytes()...)
 	if err := db.Put(key, rlp); err != nil {
 		log.Crit("Failed to store block body", "err", err)
@@ -411,7 +414,7 @@ func WriteBodyRLP(db DatabaseWriter, hash common.Hash, number uint64, rlp rlp.Ra
 }
 
 // WriteTd serializes the total difficulty of a block into the database.
-func WriteTd(db DatabaseWriter, hash common.Hash, number uint64, td *big.Int) error {
+func WriteTd(db ethdb.Putter, hash common.Hash, number uint64, td *big.Int) error {
 	data, err := rlp.EncodeToBytes(td)
 	if err != nil {
 		return err
@@ -424,7 +427,7 @@ func WriteTd(db DatabaseWriter, hash common.Hash, number uint64, td *big.Int) er
 }
 
 // WriteBlock serializes a block into the database, header and body separately.
-func WriteBlock(db DatabaseWriter, block *types.Block) error {
+func WriteBlock(db ethdb.Putter, block *types.Block) error {
 	// Store the body first to retain database consistency
 	if err := WriteBody(db, block.Hash(), block.NumberU64(), block.Body()); err != nil {
 		return err
@@ -439,7 +442,7 @@ func WriteBlock(db DatabaseWriter, block *types.Block) error {
 // WriteBlockReceipts stores all the transaction receipts belonging to a block
 // as a single receipt slice. This is used during chain reorganisations for
 // rescheduling dropped transactions.
-func WriteBlockReceipts(db DatabaseWriter, hash common.Hash, number uint64, receipts types.Receipts) error {
+func WriteBlockReceipts(db ethdb.Putter, hash common.Hash, number uint64, receipts types.Receipts) error {
 	// Convert the receipts into their storage form and serialize them
 	storageReceipts := make([]*types.ReceiptForStorage, len(receipts))
 	for i, receipt := range receipts {
@@ -459,9 +462,7 @@ func WriteBlockReceipts(db DatabaseWriter, hash common.Hash, number uint64, rece
 
 // WriteTxLookupEntries stores a positional metadata for every transaction from
 // a block, enabling hash based transaction and receipt lookups.
-func WriteTxLookupEntries(db ethdb.Database, block *types.Block) error {
-	batch := db.NewBatch()
-
+func WriteTxLookupEntries(db ethdb.Putter, block *types.Block) error {
 	// Iterate over each transaction and encode its metadata
 	for i, tx := range block.Transactions() {
 		entry := txLookupEntry{
@@ -473,20 +474,16 @@ func WriteTxLookupEntries(db ethdb.Database, block *types.Block) error {
 		if err != nil {
 			return err
 		}
-		if err := batch.Put(append(lookupPrefix, tx.Hash().Bytes()...), data); err != nil {
+		if err := db.Put(append(lookupPrefix, tx.Hash().Bytes()...), data); err != nil {
 			return err
 		}
 	}
-	// Write the scheduled data into the database
-	if err := batch.Write(); err != nil {
-		log.Crit("Failed to store lookup entries", "err", err)
-	}
 	return nil
 }
 
 // WriteBloomBits writes the compressed bloom bits vector belonging to the given
 // section and bit index.
-func WriteBloomBits(db DatabaseWriter, bit uint, section uint64, head common.Hash, bits []byte) {
+func WriteBloomBits(db ethdb.Putter, bit uint, section uint64, head common.Hash, bits []byte) {
 	key := append(append(bloomBitsPrefix, make([]byte, 10)...), head.Bytes()...)
 
 	binary.BigEndian.PutUint16(key[1:], uint16(bit))
@@ -572,13 +569,13 @@ func GetBlockChainVersion(db DatabaseReader) int {
 }
 
 // WriteBlockChainVersion writes vsn as the version number to db.
-func WriteBlockChainVersion(db DatabaseWriter, vsn int) {
+func WriteBlockChainVersion(db ethdb.Putter, vsn int) {
 	enc, _ := rlp.EncodeToBytes(uint(vsn))
 	db.Put([]byte("BlockchainVersion"), enc)
 }
 
 // WriteChainConfig writes the chain config settings to the database.
-func WriteChainConfig(db DatabaseWriter, hash common.Hash, cfg *params.ChainConfig) error {
+func WriteChainConfig(db ethdb.Putter, hash common.Hash, cfg *params.ChainConfig) error {
 	// short circuit and ignore if nil config. GetChainConfig
 	// will return a default.
 	if cfg == nil {
diff --git a/core/headerchain.go b/core/headerchain.go
index 6ec44b61d5..0e5215293d 100644
--- a/core/headerchain.go
+++ b/core/headerchain.go
@@ -267,7 +267,7 @@ func (hc *HeaderChain) InsertHeaderChain(chain []*types.Header, writeHeader WhCa
 			return i, errors.New("aborted")
 		}
 		// If the header's already known, skip it, otherwise store
-		if hc.GetHeader(header.Hash(), header.Number.Uint64()) != nil {
+		if hc.HasHeader(header.Hash(), header.Number.Uint64()) {
 			stats.ignored++
 			continue
 		}
@@ -361,10 +361,13 @@ func (hc *HeaderChain) GetHeaderByHash(hash common.Hash) *types.Header {
 	return hc.GetHeader(hash, hc.GetBlockNumber(hash))
 }
 
-// HasHeader checks if a block header is present in the database or not, caching
-// it if present.
-func (hc *HeaderChain) HasHeader(hash common.Hash) bool {
-	return hc.GetHeaderByHash(hash) != nil
+// HasHeader checks if a block header is present in the database or not.
+func (hc *HeaderChain) HasHeader(hash common.Hash, number uint64) bool {
+	if hc.numberCache.Contains(hash) || hc.headerCache.Contains(hash) {
+		return true
+	}
+	ok, _ := hc.chainDb.Has(headerKey(hash, number))
+	return ok
 }
 
 // GetHeaderByNumber retrieves a block header from the database by number,
diff --git a/core/state/sync.go b/core/state/sync.go
index 2c29d706aa..28fcf6ae05 100644
--- a/core/state/sync.go
+++ b/core/state/sync.go
@@ -18,60 +18,24 @@ package state
 
 import (
 	"bytes"
-	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
 )
 
-// StateSync is the main state synchronisation scheduler, which provides yet the
-// unknown state hashes to retrieve, accepts node data associated with said hashes
-// and reconstructs the state database step by step until all is done.
-type StateSync trie.TrieSync
-
 // NewStateSync create a new state trie download scheduler.
-func NewStateSync(root common.Hash, database trie.DatabaseReader) *StateSync {
+func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.TrieSync {
 	var syncer *trie.TrieSync
-
 	callback := func(leaf []byte, parent common.Hash) error {
-		var obj struct {
-			Nonce    uint64
-			Balance  *big.Int
-			Root     common.Hash
-			CodeHash []byte
-		}
+		var obj Account
 		if err := rlp.Decode(bytes.NewReader(leaf), &obj); err != nil {
 			return err
 		}
 		syncer.AddSubTrie(obj.Root, 64, parent, nil)
 		syncer.AddRawEntry(common.BytesToHash(obj.CodeHash), 64, parent)
-
 		return nil
 	}
 	syncer = trie.NewTrieSync(root, database, callback)
-	return (*StateSync)(syncer)
-}
-
-// Missing retrieves the known missing nodes from the state trie for retrieval.
-func (s *StateSync) Missing(max int) []common.Hash {
-	return (*trie.TrieSync)(s).Missing(max)
-}
-
-// Process injects a batch of retrieved trie nodes data, returning if something
-// was committed to the memcache and also the index of an entry if processing of
-// it failed.
-func (s *StateSync) Process(list []trie.SyncResult) (bool, int, error) {
-	return (*trie.TrieSync)(s).Process(list)
-}
-
-// Commit flushes the data stored in the internal memcache out to persistent
-// storage, returning th enumber of items written and any occurred error.
-func (s *StateSync) Commit(dbw trie.DatabaseWriter) (int, error) {
-	return (*trie.TrieSync)(s).Commit(dbw)
-}
-
-// Pending returns the number of state entries currently pending for download.
-func (s *StateSync) Pending() int {
-	return (*trie.TrieSync)(s).Pending()
+	return syncer
 }
diff --git a/core/state_processor.go b/core/state_processor.go
index 4115eab8cb..689c83785f 100644
--- a/core/state_processor.go
+++ b/core/state_processor.go
@@ -105,7 +105,7 @@ func ApplyTransaction(config *params.ChainConfig, bc *BlockChain, author *common
 
 	// Update the state with pending changes
 	var root []byte
-	if config.IsMetropolis(header.Number) {
+	if config.IsByzantium(header.Number) {
 		statedb.Finalise(true)
 	} else {
 		root = statedb.IntermediateRoot(config.IsEIP158(header.Number)).Bytes()
diff --git a/core/types/receipt.go b/core/types/receipt.go
index 4f3b7357ed..e179fe0cfd 100644
--- a/core/types/receipt.go
+++ b/core/types/receipt.go
@@ -79,7 +79,7 @@ func NewReceipt(root []byte, failed bool, cumulativeGasUsed *big.Int) *Receipt {
 }
 
 // EncodeRLP implements rlp.Encoder, and flattens the consensus fields of a receipt
-// into an RLP stream. If no post state is present, metropolis fork is assumed.
+// into an RLP stream. If no post state is present, byzantium fork is assumed.
 func (r *Receipt) EncodeRLP(w io.Writer) error {
 	return rlp.Encode(w, &receiptRLP{r.statusEncoding(), r.CumulativeGasUsed, r.Bloom, r.Logs})
 }
diff --git a/core/types/transaction.go b/core/types/transaction.go
index 947fc85d60..7f54860fc0 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -381,28 +381,32 @@ func (s *TxByPrice) Pop() interface{} {
 // transactions in a profit-maximising sorted order, while supporting removing
 // entire batches of transactions for non-executable accounts.
 type TransactionsByPriceAndNonce struct {
-	txs   map[common.Address]Transactions // Per account nonce-sorted list of transactions
-	heads TxByPrice                       // Next transaction for each unique account (price heap)
+	txs    map[common.Address]Transactions // Per account nonce-sorted list of transactions
+	heads  TxByPrice                       // Next transaction for each unique account (price heap)
+	signer Signer                          // Signer for the set of transactions
 }
 
 // NewTransactionsByPriceAndNonce creates a transaction set that can retrieve
 // price sorted transactions in a nonce-honouring way.
 //
 // Note, the input map is reowned so the caller should not interact any more with
-// if after providng it to the constructor.
-func NewTransactionsByPriceAndNonce(txs map[common.Address]Transactions) *TransactionsByPriceAndNonce {
+// if after providing it to the constructor.
+func NewTransactionsByPriceAndNonce(signer Signer, txs map[common.Address]Transactions) *TransactionsByPriceAndNonce {
 	// Initialize a price based heap with the head transactions
 	heads := make(TxByPrice, 0, len(txs))
-	for acc, accTxs := range txs {
+	for _, accTxs := range txs {
 		heads = append(heads, accTxs[0])
+		// Ensure the sender address is from the signer
+		acc, _ := Sender(signer, accTxs[0])
 		txs[acc] = accTxs[1:]
 	}
 	heap.Init(&heads)
 
 	// Assemble and return the transaction set
 	return &TransactionsByPriceAndNonce{
-		txs:   txs,
-		heads: heads,
+		txs:    txs,
+		heads:  heads,
+		signer: signer,
 	}
 }
 
@@ -416,9 +420,7 @@ func (t *TransactionsByPriceAndNonce) Peek() *Transaction {
 
 // Shift replaces the current best head with the next one from the same account.
 func (t *TransactionsByPriceAndNonce) Shift() {
-	signer := deriveSigner(t.heads[0].data.V)
-	// derive signer but don't cache.
-	acc, _ := Sender(signer, t.heads[0]) // we only sort valid txs so this cannot fail
+	acc, _ := Sender(t.signer, t.heads[0])
 	if txs, ok := t.txs[acc]; ok && len(txs) > 0 {
 		t.heads[0], t.txs[acc] = txs[0], txs[1:]
 		heap.Fix(&t.heads, 0)
diff --git a/core/types/transaction_test.go b/core/types/transaction_test.go
index edbe171e6f..df9d7ffd18 100644
--- a/core/types/transaction_test.go
+++ b/core/types/transaction_test.go
@@ -143,7 +143,7 @@ func TestTransactionPriceNonceSort(t *testing.T) {
 		}
 	}
 	// Sort the transactions and cross check the nonce ordering
-	txset := NewTransactionsByPriceAndNonce(groups)
+	txset := NewTransactionsByPriceAndNonce(signer, groups)
 
 	txs := Transactions{}
 	for {
diff --git a/core/vm/contracts.go b/core/vm/contracts.go
index 790d42bbe6..7344b6043c 100644
--- a/core/vm/contracts.go
+++ b/core/vm/contracts.go
@@ -46,9 +46,9 @@ var PrecompiledContractsHomestead = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{4}): &dataCopy{},
 }
 
-// PrecompiledContractsMetropolis contains the default set of pre-compiled Ethereum
-// contracts used in the Metropolis release.
-var PrecompiledContractsMetropolis = map[common.Address]PrecompiledContract{
+// PrecompiledContractsByzantium contains the default set of pre-compiled Ethereum
+// contracts used in the Byzantium release.
+var PrecompiledContractsByzantium = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{1}): &ecrecover{},
 	common.BytesToAddress([]byte{2}): &sha256hash{},
 	common.BytesToAddress([]byte{3}): &ripemd160hash{},
diff --git a/core/vm/contracts_test.go b/core/vm/contracts_test.go
index 880d7324ae..513651835a 100644
--- a/core/vm/contracts_test.go
+++ b/core/vm/contracts_test.go
@@ -321,7 +321,7 @@ var bn256PairingTests = []precompiledTest{
 }
 
 func testPrecompiled(addr string, test precompiledTest, t *testing.T) {
-	p := PrecompiledContractsMetropolis[common.HexToAddress(addr)]
+	p := PrecompiledContractsByzantium[common.HexToAddress(addr)]
 	in := common.Hex2Bytes(test.input)
 	contract := NewContract(AccountRef(common.HexToAddress("1337")),
 		nil, new(big.Int), p.RequiredGas(in))
@@ -338,7 +338,7 @@ func benchmarkPrecompiled(addr string, test precompiledTest, bench *testing.B) {
 	if test.noBenchmark {
 		return
 	}
-	p := PrecompiledContractsMetropolis[common.HexToAddress(addr)]
+	p := PrecompiledContractsByzantium[common.HexToAddress(addr)]
 	in := common.Hex2Bytes(test.input)
 	reqGas := p.RequiredGas(in)
 	contract := NewContract(AccountRef(common.HexToAddress("1337")),
diff --git a/core/vm/evm.go b/core/vm/evm.go
index 495d9beea1..093c7d4c14 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -41,8 +41,8 @@ type (
 func run(evm *EVM, snapshot int, contract *Contract, input []byte) ([]byte, error) {
 	if contract.CodeAddr != nil {
 		precompiles := PrecompiledContractsHomestead
-		if evm.ChainConfig().IsMetropolis(evm.BlockNumber) {
-			precompiles = PrecompiledContractsMetropolis
+		if evm.ChainConfig().IsByzantium(evm.BlockNumber) {
+			precompiles = PrecompiledContractsByzantium
 		}
 		if p := precompiles[*contract.CodeAddr]; p != nil {
 			return RunPrecompiledContract(p, input, contract)
@@ -151,8 +151,8 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 	)
 	if !evm.StateDB.Exist(addr) {
 		precompiles := PrecompiledContractsHomestead
-		if evm.ChainConfig().IsMetropolis(evm.BlockNumber) {
-			precompiles = PrecompiledContractsMetropolis
+		if evm.ChainConfig().IsByzantium(evm.BlockNumber) {
+			precompiles = PrecompiledContractsByzantium
 		}
 		if precompiles[addr] == nil && evm.ChainConfig().IsEIP158(evm.BlockNumber) && value.Sign() == 0 {
 			return nil, gas, nil
@@ -299,9 +299,6 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 
 // Create creates a new contract using code as deployment code.
 func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
-	if evm.vmConfig.NoRecursion && evm.depth > 0 {
-		return nil, common.Address{}, gas, nil
-	}
 
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
@@ -334,6 +331,9 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 	contract := NewContract(caller, AccountRef(contractAddr), value, gas)
 	contract.SetCallCode(&contractAddr, crypto.Keccak256Hash(code), code)
 
+	if evm.vmConfig.NoRecursion && evm.depth > 0 {
+		return nil, contractAddr, gas, nil
+	}
 	ret, err = run(evm, snapshot, contract, nil)
 	// check whether the max code size has been exceeded
 	maxCodeSizeExceeded := evm.ChainConfig().IsEIP158(evm.BlockNumber) && len(ret) > params.MaxCodeSize
diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
index 13712295c9..0d8e295a52 100644
--- a/core/vm/gas_table.go
+++ b/core/vm/gas_table.go
@@ -324,7 +324,7 @@ func gasCall(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem
 		eip158         = evm.ChainConfig().IsEIP158(evm.BlockNumber)
 	)
 	if eip158 {
-		if transfersValue && evm.StateDB.Empty(address)  {
+		if transfersValue && evm.StateDB.Empty(address) {
 			gas += params.CallNewAccountGas
 		}
 	} else if !evm.StateDB.Exist(address) {
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index d3e24a7a45..b0d796a44b 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -70,8 +70,8 @@ func NewInterpreter(evm *EVM, cfg Config) *Interpreter {
 	// we'll set the default jump table.
 	if !cfg.JumpTable[STOP].valid {
 		switch {
-		case evm.ChainConfig().IsMetropolis(evm.BlockNumber):
-			cfg.JumpTable = metropolisInstructionSet
+		case evm.ChainConfig().IsByzantium(evm.BlockNumber):
+			cfg.JumpTable = byzantiumInstructionSet
 		case evm.ChainConfig().IsHomestead(evm.BlockNumber):
 			cfg.JumpTable = homesteadInstructionSet
 		default:
@@ -88,7 +88,7 @@ func NewInterpreter(evm *EVM, cfg Config) *Interpreter {
 }
 
 func (in *Interpreter) enforceRestrictions(op OpCode, operation operation, stack *Stack) error {
-	if in.evm.chainRules.IsMetropolis {
+	if in.evm.chainRules.IsByzantium {
 		if in.readOnly {
 			// If the interpreter is operating in readonly mode, make sure no
 			// state-modifying operation is performed. The 3rd stack item
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index f0a922912f..9ef192fdf9 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -51,14 +51,14 @@ type operation struct {
 }
 
 var (
-	frontierInstructionSet   = NewFrontierInstructionSet()
-	homesteadInstructionSet  = NewHomesteadInstructionSet()
-	metropolisInstructionSet = NewMetropolisInstructionSet()
+	frontierInstructionSet  = NewFrontierInstructionSet()
+	homesteadInstructionSet = NewHomesteadInstructionSet()
+	byzantiumInstructionSet = NewByzantiumInstructionSet()
 )
 
-// NewMetropolisInstructionSet returns the frontier, homestead and
-// metropolis instructions.
-func NewMetropolisInstructionSet() [256]operation {
+// NewByzantiumInstructionSet returns the frontier, homestead and
+// byzantium instructions.
+func NewByzantiumInstructionSet() [256]operation {
 	// instructions that can be executed during the homestead phase.
 	instructionSet := NewHomesteadInstructionSet()
 	instructionSet[STATICCALL] = operation{
diff --git a/eth/api.go b/eth/api.go
index 9904c6f536..a5b6e7076c 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -241,7 +241,7 @@ func (api *PrivateAdminAPI) ExportChain(file string) (bool, error) {
 
 func hasAllBlocks(chain *core.BlockChain, bs []*types.Block) bool {
 	for _, b := range bs {
-		if !chain.HasBlock(b.Hash()) {
+		if !chain.HasBlock(b.Hash(), b.NumberU64()) {
 			return false
 		}
 	}
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 6ac58140a3..5782d4cf53 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -156,7 +156,7 @@ type Downloader struct {
 // LightChain encapsulates functions required to synchronise a light chain.
 type LightChain interface {
 	// HasHeader verifies a header's presence in the local chain.
-	HasHeader(common.Hash) bool
+	HasHeader(h common.Hash, number uint64) bool
 
 	// GetHeaderByHash retrieves a header from the local chain.
 	GetHeaderByHash(common.Hash) *types.Header
@@ -666,7 +666,7 @@ func (d *Downloader) findAncestor(p *peerConnection, height uint64) (uint64, err
 					continue
 				}
 				// Otherwise check if we already know the header or not
-				if (d.mode == FullSync && d.blockchain.HasBlockAndState(headers[i].Hash())) || (d.mode != FullSync && d.lightchain.HasHeader(headers[i].Hash())) {
+				if (d.mode == FullSync && d.blockchain.HasBlockAndState(headers[i].Hash())) || (d.mode != FullSync && d.lightchain.HasHeader(headers[i].Hash(), headers[i].Number.Uint64())) {
 					number, hash = headers[i].Number.Uint64(), headers[i].Hash()
 
 					// If every header is known, even future ones, the peer straight out lied about its head
@@ -731,7 +731,7 @@ func (d *Downloader) findAncestor(p *peerConnection, height uint64) (uint64, err
 				arrived = true
 
 				// Modify the search interval based on the response
-				if (d.mode == FullSync && !d.blockchain.HasBlockAndState(headers[0].Hash())) || (d.mode != FullSync && !d.lightchain.HasHeader(headers[0].Hash())) {
+				if (d.mode == FullSync && !d.blockchain.HasBlockAndState(headers[0].Hash())) || (d.mode != FullSync && !d.lightchain.HasHeader(headers[0].Hash(), headers[0].Number.Uint64())) {
 					end = check
 					break
 				}
@@ -1093,6 +1093,10 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 					throttled = true
 					break
 				}
+				// Short circuit if there is no more available task.
+				if pending() == 0 {
+					break
+				}
 				// Reserve a chunk of fetches for a peer. A nil can mean either that
 				// no more headers are available, or that the peer is known not to
 				// have them.
@@ -1170,7 +1174,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 
 			// If we're already past the pivot point, this could be an attack, thread carefully
 			if rollback[len(rollback)-1].Number.Uint64() > pivot {
-				// If we didn't ever fail, lock in te pivot header (must! not! change!)
+				// If we didn't ever fail, lock in the pivot header (must! not! change!)
 				if atomic.LoadUint32(&d.fsPivotFails) == 0 {
 					for _, header := range rollback {
 						if header.Number.Uint64() == pivot {
@@ -1256,7 +1260,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 					// Collect the yet unknown headers to mark them as uncertain
 					unknown := make([]*types.Header, 0, len(headers))
 					for _, header := range chunk {
-						if !d.lightchain.HasHeader(header.Hash()) {
+						if !d.lightchain.HasHeader(header.Hash(), header.Number.Uint64()) {
 							unknown = append(unknown, header)
 						}
 					}
@@ -1392,7 +1396,6 @@ func (d *Downloader) processFastSyncContent(latest *types.Header) error {
 			stateSync.Cancel()
 			if err := d.commitPivotBlock(P); err != nil {
 				return err
-
 			}
 		}
 		if err := d.importBlockResults(afterP); err != nil {
diff --git a/eth/downloader/downloader_test.go b/eth/downloader/downloader_test.go
index d66aafe94e..58f6e9a624 100644
--- a/eth/downloader/downloader_test.go
+++ b/eth/downloader/downloader_test.go
@@ -217,7 +217,7 @@ func (dl *downloadTester) sync(id string, td *big.Int, mode SyncMode) error {
 }
 
 // HasHeader checks if a header is present in the testers canonical chain.
-func (dl *downloadTester) HasHeader(hash common.Hash) bool {
+func (dl *downloadTester) HasHeader(hash common.Hash, number uint64) bool {
 	return dl.GetHeaderByHash(hash) != nil
 }
 
diff --git a/eth/downloader/peer.go b/eth/downloader/peer.go
index d0dc9a8aa6..e638744ea5 100644
--- a/eth/downloader/peer.go
+++ b/eth/downloader/peer.go
@@ -349,9 +349,10 @@ func (p *peerConnection) Lacks(hash common.Hash) bool {
 // peerSet represents the collection of active peer participating in the chain
 // download procedure.
 type peerSet struct {
-	peers       map[string]*peerConnection
-	newPeerFeed event.Feed
-	lock        sync.RWMutex
+	peers        map[string]*peerConnection
+	newPeerFeed  event.Feed
+	peerDropFeed event.Feed
+	lock         sync.RWMutex
 }
 
 // newPeerSet creates a new peer set top track the active download sources.
@@ -361,10 +362,16 @@ func newPeerSet() *peerSet {
 	}
 }
 
+// SubscribeNewPeers subscribes to peer arrival events.
 func (ps *peerSet) SubscribeNewPeers(ch chan<- *peerConnection) event.Subscription {
 	return ps.newPeerFeed.Subscribe(ch)
 }
 
+// SubscribePeerDrops subscribes to peer departure events.
+func (ps *peerSet) SubscribePeerDrops(ch chan<- *peerConnection) event.Subscription {
+	return ps.peerDropFeed.Subscribe(ch)
+}
+
 // Reset iterates over the current peer set, and resets each of the known peers
 // to prepare for a next batch of block retrieval.
 func (ps *peerSet) Reset() {
@@ -419,12 +426,15 @@ func (ps *peerSet) Register(p *peerConnection) error {
 // actions to/from that particular entity.
 func (ps *peerSet) Unregister(id string) error {
 	ps.lock.Lock()
-	defer ps.lock.Unlock()
-
-	if _, ok := ps.peers[id]; !ok {
+	p, ok := ps.peers[id]
+	if !ok {
+		defer ps.lock.Unlock()
 		return errNotRegistered
 	}
 	delete(ps.peers, id)
+	ps.lock.Unlock()
+
+	ps.peerDropFeed.Send(p)
 	return nil
 }
 
diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index a5ce8c42df..a0b05c9be6 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/crypto/sha3"
+	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/trie"
 )
@@ -39,6 +40,7 @@ type stateReq struct {
 	timer    *time.Timer                // Timer to fire when the RTT timeout expires
 	peer     *peerConnection            // Peer that we're requesting from
 	response [][]byte                   // Response data of the peer (nil for timeouts)
+	dropped  bool                       // Flag whether the peer dropped off early
 }
 
 // timedOut returns if this request timed out.
@@ -104,6 +106,11 @@ func (d *Downloader) runStateSync(s *stateSync) *stateSync {
 	go s.run()
 	defer s.Cancel()
 
+	// Listen for peer departure events to cancel assigned tasks
+	peerDrop := make(chan *peerConnection, 1024)
+	peerSub := s.d.peers.SubscribePeerDrops(peerDrop)
+	defer peerSub.Unsubscribe()
+
 	for {
 		// Enable sending of the first buffered element if there is one.
 		var (
@@ -142,6 +149,20 @@ func (d *Downloader) runStateSync(s *stateSync) *stateSync {
 			finished = append(finished, req)
 			delete(active, pack.PeerId())
 
+			// Handle dropped peer connections:
+		case p := <-peerDrop:
+			// Skip if no request is currently pending
+			req := active[p.id]
+			if req == nil {
+				continue
+			}
+			// Finalize the request and queue up for processing
+			req.timer.Stop()
+			req.dropped = true
+
+			finished = append(finished, req)
+			delete(active, p.id)
+
 		// Handle timed-out requests:
 		case req := <-timeout:
 			// If the peer is already requesting something else, ignore the stale timeout.
@@ -166,6 +187,9 @@ func (d *Downloader) runStateSync(s *stateSync) *stateSync {
 				log.Warn("Busy peer assigned new state fetch", "peer", old.peer.id)
 
 				// Make sure the previous one doesn't get siletly lost
+				old.timer.Stop()
+				old.dropped = true
+
 				finished = append(finished, old)
 			}
 			// Start a timer to notify the sync loop if the peer stalled.
@@ -187,10 +211,13 @@ func (d *Downloader) runStateSync(s *stateSync) *stateSync {
 type stateSync struct {
 	d *Downloader // Downloader instance to access and manage current peerset
 
-	sched  *state.StateSync           // State trie sync scheduler defining the tasks
+	sched  *trie.TrieSync             // State trie sync scheduler defining the tasks
 	keccak hash.Hash                  // Keccak256 hasher to verify deliveries with
 	tasks  map[common.Hash]*stateTask // Set of tasks currently queued for retrieval
 
+	numUncommitted   int
+	bytesUncommitted int
+
 	deliver    chan *stateReq // Delivery channel multiplexing peer responses
 	cancel     chan struct{}  // Channel to signal a termination request
 	cancelOnce sync.Once      // Ensures cancel only ever gets called once
@@ -252,9 +279,10 @@ func (s *stateSync) loop() error {
 
 	// Keep assigning new tasks until the sync completes or aborts
 	for s.sched.Pending() > 0 {
-		if err := s.assignTasks(); err != nil {
+		if err := s.commit(false); err != nil {
 			return err
 		}
+		s.assignTasks()
 		// Tasks assigned, wait for something to happen
 		select {
 		case <-newPeer:
@@ -264,9 +292,9 @@ func (s *stateSync) loop() error {
 			return errCancelStateFetch
 
 		case req := <-s.deliver:
-			// Response or timeout triggered, drop the peer if stalling
-			log.Trace("Received node data response", "peer", req.peer.id, "count", len(req.response), "timeout", req.timedOut())
-			if len(req.items) <= 2 && req.timedOut() {
+			// Response, disconnect or timeout triggered, drop the peer if stalling
+			log.Trace("Received node data response", "peer", req.peer.id, "count", len(req.response), "dropped", req.dropped, "timeout", !req.dropped && req.timedOut())
+			if len(req.items) <= 2 && !req.dropped && req.timedOut() {
 				// 2 items are the minimum requested, if even that times out, we've no use of
 				// this peer at the moment.
 				log.Warn("Stalling state sync, dropping peer", "peer", req.peer.id)
@@ -284,12 +312,28 @@ func (s *stateSync) loop() error {
 			}
 		}
 	}
+	return s.commit(true)
+}
+
+func (s *stateSync) commit(force bool) error {
+	if !force && s.bytesUncommitted < ethdb.IdealBatchSize {
+		return nil
+	}
+	start := time.Now()
+	b := s.d.stateDB.NewBatch()
+	s.sched.Commit(b)
+	if err := b.Write(); err != nil {
+		return fmt.Errorf("DB write error: %v", err)
+	}
+	s.updateStats(s.numUncommitted, 0, 0, time.Since(start))
+	s.numUncommitted = 0
+	s.bytesUncommitted = 0
 	return nil
 }
 
 // assignTasks attempts to assing new tasks to all idle peers, either from the
 // batch currently being retried, or fetching new data from the trie sync itself.
-func (s *stateSync) assignTasks() error {
+func (s *stateSync) assignTasks() {
 	// Iterate over all idle peers and try to assign them state fetches
 	peers, _ := s.d.peers.NodeDataIdlePeers()
 	for _, p := range peers {
@@ -301,7 +345,6 @@ func (s *stateSync) assignTasks() error {
 		// If the peer was assigned tasks to fetch, send the network request
 		if len(req.items) > 0 {
 			req.peer.log.Trace("Requesting new batch of data", "type", "state", "count", len(req.items))
-
 			select {
 			case s.d.trackStateReq <- req:
 				req.peer.FetchNodeData(req.items)
@@ -309,7 +352,6 @@ func (s *stateSync) assignTasks() error {
 			}
 		}
 	}
-	return nil
 }
 
 // fillTasks fills the given request object with a maximum of n state download
@@ -347,11 +389,11 @@ func (s *stateSync) fillTasks(n int, req *stateReq) {
 // delivered.
 func (s *stateSync) process(req *stateReq) (bool, error) {
 	// Collect processing stats and update progress if valid data was received
-	processed, written, duplicate, unexpected := 0, 0, 0, 0
+	duplicate, unexpected := 0, 0
 
 	defer func(start time.Time) {
-		if processed+written+duplicate+unexpected > 0 {
-			s.updateStats(processed, written, duplicate, unexpected, time.Since(start))
+		if duplicate > 0 || unexpected > 0 {
+			s.updateStats(0, duplicate, unexpected, time.Since(start))
 		}
 	}(time.Now())
 
@@ -362,7 +404,9 @@ func (s *stateSync) process(req *stateReq) (bool, error) {
 		prog, hash, err := s.processNodeData(blob)
 		switch err {
 		case nil:
-			processed++
+			s.numUncommitted++
+			s.bytesUncommitted += len(blob)
+			progress = progress || prog
 		case trie.ErrNotRequested:
 			unexpected++
 		case trie.ErrAlreadyProcessed:
@@ -370,38 +414,20 @@ func (s *stateSync) process(req *stateReq) (bool, error) {
 		default:
 			return stale, fmt.Errorf("invalid state node %s: %v", hash.TerminalString(), err)
 		}
-		if prog {
-			progress = true
-		}
 		// If the node delivered a requested item, mark the delivery non-stale
 		if _, ok := req.tasks[hash]; ok {
 			delete(req.tasks, hash)
 			stale = false
 		}
 	}
-	// If some data managed to hit the database, flush and reset failure counters
-	if progress {
-		// Flush any accumulated data out to disk
-		batch := s.d.stateDB.NewBatch()
-
-		count, err := s.sched.Commit(batch)
-		if err != nil {
-			return stale, err
-		}
-		if err := batch.Write(); err != nil {
-			return stale, err
-		}
-		written = count
-
-		// If we're inside the critical section, reset fail counter since we progressed
-		if atomic.LoadUint32(&s.d.fsPivotFails) > 1 {
-			log.Trace("Fast-sync progressed, resetting fail counter", "previous", atomic.LoadUint32(&s.d.fsPivotFails))
-			atomic.StoreUint32(&s.d.fsPivotFails, 1) // Don't ever reset to 0, as that will unlock the pivot block
-		}
+	// If we're inside the critical section, reset fail counter since we progressed.
+	if progress && atomic.LoadUint32(&s.d.fsPivotFails) > 1 {
+		log.Trace("Fast-sync progressed, resetting fail counter", "previous", atomic.LoadUint32(&s.d.fsPivotFails))
+		atomic.StoreUint32(&s.d.fsPivotFails, 1) // Don't ever reset to 0, as that will unlock the pivot block
 	}
+
 	// Put unfulfilled tasks back into the retry queue
 	npeers := s.d.peers.Len()
-
 	for hash, task := range req.tasks {
 		// If the node did deliver something, missing items may be due to a protocol
 		// limit or a previous timeout + delayed delivery. Both cases should permit
@@ -425,25 +451,25 @@ func (s *stateSync) process(req *stateReq) (bool, error) {
 // error occurred.
 func (s *stateSync) processNodeData(blob []byte) (bool, common.Hash, error) {
 	res := trie.SyncResult{Data: blob}
-
 	s.keccak.Reset()
 	s.keccak.Write(blob)
 	s.keccak.Sum(res.Hash[:0])
-
 	committed, _, err := s.sched.Process([]trie.SyncResult{res})
 	return committed, res.Hash, err
 }
 
 // updateStats bumps the various state sync progress counters and displays a log
 // message for the user to see.
-func (s *stateSync) updateStats(processed, written, duplicate, unexpected int, duration time.Duration) {
+func (s *stateSync) updateStats(written, duplicate, unexpected int, duration time.Duration) {
 	s.d.syncStatsLock.Lock()
 	defer s.d.syncStatsLock.Unlock()
 
 	s.d.syncStatsState.pending = uint64(s.sched.Pending())
-	s.d.syncStatsState.processed += uint64(processed)
+	s.d.syncStatsState.processed += uint64(written)
 	s.d.syncStatsState.duplicate += uint64(duplicate)
 	s.d.syncStatsState.unexpected += uint64(unexpected)
 
-	log.Info("Imported new state entries", "count", processed, "flushed", written, "elapsed", common.PrettyDuration(duration), "processed", s.d.syncStatsState.processed, "pending", s.d.syncStatsState.pending, "retry", len(s.tasks), "duplicate", s.d.syncStatsState.duplicate, "unexpected", s.d.syncStatsState.unexpected)
+	if written > 0 || duplicate > 0 || unexpected > 0 {
+		log.Info("Imported new state entries", "count", written, "elapsed", common.PrettyDuration(duration), "processed", s.d.syncStatsState.processed, "pending", s.d.syncStatsState.pending, "retry", len(s.tasks), "duplicate", s.d.syncStatsState.duplicate, "unexpected", s.d.syncStatsState.unexpected)
+	}
 }
diff --git a/eth/handler.go b/eth/handler.go
index 28ae208c06..cee719ddb6 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -609,7 +609,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		// Schedule all the unknown hashes for retrieval
 		unknown := make(newBlockHashesData, 0, len(announces))
 		for _, block := range announces {
-			if !pm.blockchain.HasBlock(block.Hash) {
+			if !pm.blockchain.HasBlock(block.Hash, block.Number) {
 				unknown = append(unknown, block)
 			}
 		}
@@ -699,7 +699,7 @@ func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
 		return
 	}
 	// Otherwise if the block is indeed in out own chain, announce it
-	if pm.blockchain.HasBlock(hash) {
+	if pm.blockchain.HasBlock(hash, block.NumberU64()) {
 		for _, peer := range peers {
 			peer.SendNewBlockHashes([]common.Hash{hash}, []uint64{block.NumberU64()})
 		}
diff --git a/eth/sync.go b/eth/sync.go
index 7442f912c7..a8ae646170 100644
--- a/eth/sync.go
+++ b/eth/sync.go
@@ -188,7 +188,17 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 		atomic.StoreUint32(&pm.fastSync, 1)
 		mode = downloader.FastSync
 	}
-	if err := pm.downloader.Synchronise(peer.id, pHead, pTd, mode); err != nil {
+	// Run the sync cycle, and disable fast sync if we've went past the pivot block
+	err := pm.downloader.Synchronise(peer.id, pHead, pTd, mode)
+
+	if atomic.LoadUint32(&pm.fastSync) == 1 {
+		// Disable fast sync if we indeed have something in our chain
+		if pm.blockchain.CurrentBlock().NumberU64() > 0 {
+			log.Info("Fast sync complete, auto disabling")
+			atomic.StoreUint32(&pm.fastSync, 0)
+		}
+	}
+	if err != nil {
 		return
 	}
 	atomic.StoreUint32(&pm.acceptTxs, 1) // Mark initial sync done
@@ -201,12 +211,4 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 		// more reliably update peers or the local TD state.
 		go pm.BroadcastBlock(head, false)
 	}
-	// If fast sync was enabled, and we synced up, disable it
-	if atomic.LoadUint32(&pm.fastSync) == 1 {
-		// Disable fast sync if we indeed have something in our chain
-		if pm.blockchain.CurrentBlock().NumberU64() > 0 {
-			log.Info("Fast sync complete, auto disabling")
-			atomic.StoreUint32(&pm.fastSync, 0)
-		}
-	}
 }
diff --git a/ethdb/database.go b/ethdb/database.go
index 7d5fb0b9ef..93755dd7e3 100644
--- a/ethdb/database.go
+++ b/ethdb/database.go
@@ -109,6 +109,10 @@ func (db *LDBDatabase) Put(key []byte, value []byte) error {
 	return db.db.Put(key, value, nil)
 }
 
+func (db *LDBDatabase) Has(key []byte) (bool, error) {
+	return db.db.Has(key, nil)
+}
+
 // Get returns the given key if it's present.
 func (db *LDBDatabase) Get(key []byte) ([]byte, error) {
 	// Measure the database get latency, if requested
@@ -271,19 +275,19 @@ func (db *LDBDatabase) meter(refresh time.Duration) {
 	}
 }
 
-// TODO: remove this stuff and expose leveldb directly
-
 func (db *LDBDatabase) NewBatch() Batch {
 	return &ldbBatch{db: db.db, b: new(leveldb.Batch)}
 }
 
 type ldbBatch struct {
-	db *leveldb.DB
-	b  *leveldb.Batch
+	db   *leveldb.DB
+	b    *leveldb.Batch
+	size int
 }
 
 func (b *ldbBatch) Put(key, value []byte) error {
 	b.b.Put(key, value)
+	b.size += len(value)
 	return nil
 }
 
@@ -291,6 +295,10 @@ func (b *ldbBatch) Write() error {
 	return b.db.Write(b.b, nil)
 }
 
+func (b *ldbBatch) ValueSize() int {
+	return b.size
+}
+
 type table struct {
 	db     Database
 	prefix string
@@ -309,6 +317,10 @@ func (dt *table) Put(key []byte, value []byte) error {
 	return dt.db.Put(append([]byte(dt.prefix), key...), value)
 }
 
+func (dt *table) Has(key []byte) (bool, error) {
+	return dt.db.Has(append([]byte(dt.prefix), key...))
+}
+
 func (dt *table) Get(key []byte) ([]byte, error) {
 	return dt.db.Get(append([]byte(dt.prefix), key...))
 }
@@ -342,3 +354,7 @@ func (tb *tableBatch) Put(key, value []byte) error {
 func (tb *tableBatch) Write() error {
 	return tb.batch.Write()
 }
+
+func (tb *tableBatch) ValueSize() int {
+	return tb.batch.ValueSize()
+}
diff --git a/ethdb/interface.go b/ethdb/interface.go
index f4b787a52a..99a5b770d5 100644
--- a/ethdb/interface.go
+++ b/ethdb/interface.go
@@ -16,15 +16,29 @@
 
 package ethdb
 
-type Database interface {
+// Code using batches should try to add this much data to the batch.
+// The value was determined empirically.
+const IdealBatchSize = 100 * 1024
+
+// Putter wraps the database write operation supported by both batches and regular databases.
+type Putter interface {
 	Put(key []byte, value []byte) error
+}
+
+// Database wraps all database operations. All methods are safe for concurrent use.
+type Database interface {
+	Putter
 	Get(key []byte) ([]byte, error)
+	Has(key []byte) (bool, error)
 	Delete(key []byte) error
 	Close()
 	NewBatch() Batch
 }
 
+// Batch is a write-only database that commits changes to its host database
+// when Write is called. Batch cannot be used concurrently.
 type Batch interface {
-	Put(key, value []byte) error
+	Putter
+	ValueSize() int // amount of data in the batch
 	Write() error
 }
diff --git a/ethdb/memory_database.go b/ethdb/memory_database.go
index 11b0937248..699bd0c9fd 100644
--- a/ethdb/memory_database.go
+++ b/ethdb/memory_database.go
@@ -45,6 +45,14 @@ func (db *MemDatabase) Put(key []byte, value []byte) error {
 	return nil
 }
 
+func (db *MemDatabase) Has(key []byte) (bool, error) {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	_, ok := db.db[string(key)]
+	return ok, nil
+}
+
 func (db *MemDatabase) Get(key []byte) ([]byte, error) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
@@ -93,21 +101,16 @@ type kv struct{ k, v []byte }
 type memBatch struct {
 	db     *MemDatabase
 	writes []kv
-	lock   sync.RWMutex
+	size   int
 }
 
 func (b *memBatch) Put(key, value []byte) error {
-	b.lock.Lock()
-	defer b.lock.Unlock()
-
 	b.writes = append(b.writes, kv{common.CopyBytes(key), common.CopyBytes(value)})
+	b.size += len(value)
 	return nil
 }
 
 func (b *memBatch) Write() error {
-	b.lock.RLock()
-	defer b.lock.RUnlock()
-
 	b.db.lock.Lock()
 	defer b.db.lock.Unlock()
 
@@ -116,3 +119,7 @@ func (b *memBatch) Write() error {
 	}
 	return nil
 }
+
+func (b *memBatch) ValueSize() int {
+	return b.size
+}
diff --git a/interfaces.go b/interfaces.go
index 744f07b95a..67f236ef75 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -102,7 +102,7 @@ type SyncProgress struct {
 	CurrentBlock  uint64 // Current block number where sync is at
 	HighestBlock  uint64 // Highest alleged block number in the chain
 	PulledStates  uint64 // Number of state trie entries already downloaded
-	KnownStates   uint64 // Total number os state trie entries known about
+	KnownStates   uint64 // Total number of state trie entries known about
 }
 
 // ChainSyncReader wraps access to the node's current sync status. If there's no
@@ -129,7 +129,7 @@ type ContractCaller interface {
 	CallContract(ctx context.Context, call CallMsg, blockNumber *big.Int) ([]byte, error)
 }
 
-// FilterQuery contains options for contact log filtering.
+// FilterQuery contains options for contract log filtering.
 type FilterQuery struct {
 	FromBlock *big.Int         // beginning of the queried range, nil means genesis block
 	ToBlock   *big.Int         // end of the range, nil means latest block
diff --git a/internal/debug/api.go b/internal/debug/api.go
index 8b7693f6a4..3547b05641 100644
--- a/internal/debug/api.go
+++ b/internal/debug/api.go
@@ -176,6 +176,17 @@ func (*HandlerT) Stacks() string {
 	return string(buf)
 }
 
+// FreeOSMemory returns unused memory to the OS.
+func (*HandlerT) FreeOSMemory() {
+	debug.FreeOSMemory()
+}
+
+// SetGCPercent sets the garbage collection target percentage. It returns the previous
+// setting. A negative value disables GC.
+func (*HandlerT) SetGCPercent(v int) int {
+	return debug.SetGCPercent(v)
+}
+
 func writeProfile(name, file string) error {
 	p := pprof.Lookup(name)
 	log.Info("Writing profile records", "count", p.Count(), "type", name, "dump", file)
diff --git a/internal/web3ext/web3ext.go b/internal/web3ext/web3ext.go
index 9ec716be20..1ae6e2d738 100644
--- a/internal/web3ext/web3ext.go
+++ b/internal/web3ext/web3ext.go
@@ -34,58 +34,56 @@ var Modules = map[string]string{
 
 const Chequebook_JS = `
 web3._extend({
-  property: 'chequebook',
-  methods:
-  [
-    new web3._extend.Method({
-      name: 'deposit',
-      call: 'chequebook_deposit',
-      params: 1,
-      inputFormatter: [null]
-    }),
-    new web3._extend.Property({
+	property: 'chequebook',
+	methods: [
+		new web3._extend.Method({
+			name: 'deposit',
+			call: 'chequebook_deposit',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Property({
 			name: 'balance',
 			getter: 'chequebook_balance',
-				outputFormatter: web3._extend.utils.toDecimal
+			outputFormatter: web3._extend.utils.toDecimal
 		}),
-    new web3._extend.Method({
-      name: 'cash',
-      call: 'chequebook_cash',
-      params: 1,
-      inputFormatter: [null]
-    }),
-    new web3._extend.Method({
-      name: 'issue',
-      call: 'chequebook_issue',
-      params: 2,
-      inputFormatter: [null, null]
-    }),
-  ]
+		new web3._extend.Method({
+			name: 'cash',
+			call: 'chequebook_cash',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'issue',
+			call: 'chequebook_issue',
+			params: 2,
+			inputFormatter: [null, null]
+		}),
+	]
 });
 `
 
 const Clique_JS = `
 web3._extend({
-  property: 'clique',
-  methods:
-  [
+	property: 'clique',
+	methods: [
 		new web3._extend.Method({
 			name: 'getSnapshot',
 			call: 'clique_getSnapshot',
 			params: 1,
-      inputFormatter: [null]
+			inputFormatter: [null]
 		}),
 		new web3._extend.Method({
 			name: 'getSnapshotAtHash',
 			call: 'clique_getSnapshotAtHash',
 			params: 1
 		}),
-    new web3._extend.Method({
-      name: 'getSigners',
-      call: 'clique_getSigners',
-      params: 1,
-      inputFormatter: [null]
-    }),
+		new web3._extend.Method({
+			name: 'getSigners',
+			call: 'clique_getSigners',
+			params: 1,
+			inputFormatter: [null]
+		}),
 		new web3._extend.Method({
 			name: 'getSignersAtHash',
 			call: 'clique_getSignersAtHash',
@@ -100,10 +98,9 @@ web3._extend({
 			name: 'discard',
 			call: 'clique_discard',
 			params: 1
-		})
-  ],
-	properties:
-	[
+		}),
+	],
+	properties: [
 		new web3._extend.Property({
 			name: 'proposals',
 			getter: 'clique_proposals'
@@ -115,8 +112,7 @@ web3._extend({
 const Admin_JS = `
 web3._extend({
 	property: 'admin',
-	methods:
-	[
+	methods: [
 		new web3._extend.Method({
 			name: 'addPeer',
 			call: 'admin_addPeer',
@@ -162,10 +158,9 @@ web3._extend({
 		new web3._extend.Method({
 			name: 'stopWS',
 			call: 'admin_stopWS'
-		})
+		}),
 	],
-	properties:
-	[
+	properties: [
 		new web3._extend.Property({
 			name: 'nodeInfo',
 			getter: 'admin_nodeInfo'
@@ -177,7 +172,7 @@ web3._extend({
 		new web3._extend.Property({
 			name: 'datadir',
 			getter: 'admin_datadir'
-		})
+		}),
 	]
 });
 `
@@ -185,8 +180,7 @@ web3._extend({
 const Debug_JS = `
 web3._extend({
 	property: 'debug',
-	methods:
-	[
+	methods: [
 		new web3._extend.Method({
 			name: 'printBlock',
 			call: 'debug_printBlock',
@@ -268,6 +262,16 @@ web3._extend({
 			params: 0,
 			outputFormatter: console.log
 		}),
+		new web3._extend.Method({
+			name: 'freeOSMemory',
+			call: 'debug_freeOSMemory',
+			params: 0,
+		}),
+		new web3._extend.Method({
+			name: 'setGCPercent',
+			call: 'debug_setGCPercent',
+			params: 1,
+		}),
 		new web3._extend.Method({
 			name: 'memStats',
 			call: 'debug_memStats',
@@ -358,8 +362,7 @@ web3._extend({
 const Eth_JS = `
 web3._extend({
 	property: 'eth',
-	methods:
-	[
+	methods: [
 		new web3._extend.Method({
 			name: 'sign',
 			call: 'eth_sign',
@@ -396,10 +399,9 @@ web3._extend({
 			},
 			params: 2,
 			inputFormatter: [web3._extend.formatters.inputBlockNumberFormatter, web3._extend.utils.toHex]
-		})
+		}),
 	],
-	properties:
-	[
+	properties: [
 		new web3._extend.Property({
 			name: 'pendingTransactions',
 			getter: 'eth_pendingTransactions',
@@ -411,7 +413,7 @@ web3._extend({
 				}
 				return formatted;
 			}
-		})
+		}),
 	]
 });
 `
@@ -419,8 +421,7 @@ web3._extend({
 const Miner_JS = `
 web3._extend({
 	property: 'miner',
-	methods:
-	[
+	methods: [
 		new web3._extend.Method({
 			name: 'start',
 			call: 'miner_start',
@@ -451,7 +452,7 @@ web3._extend({
 		new web3._extend.Method({
 			name: 'getHashrate',
 			call: 'miner_getHashrate'
-		})
+		}),
 	],
 	properties: []
 });
@@ -461,12 +462,11 @@ const Net_JS = `
 web3._extend({
 	property: 'net',
 	methods: [],
-	properties:
-	[
+	properties: [
 		new web3._extend.Property({
 			name: 'version',
 			getter: 'net_version'
-		})
+		}),
 	]
 });
 `
@@ -474,8 +474,7 @@ web3._extend({
 const Personal_JS = `
 web3._extend({
 	property: 'personal',
-	methods:
-	[
+	methods: [
 		new web3._extend.Method({
 			name: 'importRawKey',
 			call: 'personal_importRawKey',
@@ -501,14 +500,13 @@ web3._extend({
 			name: 'deriveAccount',
 			call: 'personal_deriveAccount',
 			params: 3
-		})
+		}),
 	],
-	properties:
-	[
+	properties: [
 		new web3._extend.Property({
 			name: 'listWallets',
 			getter: 'personal_listWallets'
-		})
+		}),
 	]
 })
 `
@@ -517,12 +515,11 @@ const RPC_JS = `
 web3._extend({
 	property: 'rpc',
 	methods: [],
-	properties:
-	[
+	properties: [
 		new web3._extend.Property({
 			name: 'modules',
 			getter: 'rpc_modules'
-		})
+		}),
 	]
 });
 `
@@ -566,7 +563,7 @@ web3._extend({
 			name: 'listmounts',
 			call: 'swarmfs_listmounts',
 			params: 0
-		})
+		}),
 	]
 });
 `
@@ -593,7 +590,7 @@ web3._extend({
 				status.queued = web3._extend.utils.toDecimal(status.queued);
 				return status;
 			}
-		})
+		}),
 	]
 });
 `
diff --git a/les/handler.go b/les/handler.go
index 1a75cd369d..df7eb6af51 100644
--- a/les/handler.go
+++ b/les/handler.go
@@ -70,7 +70,7 @@ func errResp(code errCode, format string, v ...interface{}) error {
 }
 
 type BlockChain interface {
-	HasHeader(hash common.Hash) bool
+	HasHeader(hash common.Hash, number uint64) bool
 	GetHeader(hash common.Hash, number uint64) *types.Header
 	GetHeaderByHash(hash common.Hash) *types.Header
 	CurrentHeader() *types.Header
diff --git a/light/lightchain.go b/light/lightchain.go
index df194ecadf..4c877a771a 100644
--- a/light/lightchain.go
+++ b/light/lightchain.go
@@ -97,9 +97,14 @@ func NewLightChain(odr OdrBackend, config *params.ChainConfig, engine consensus.
 	}
 	if bc.genesisBlock.Hash() == params.MainnetGenesisHash {
 		// add trusted CHT
-		WriteTrustedCht(bc.chainDb, TrustedCht{Number: 805, Root: common.HexToHash("85e4286fe0a730390245c49de8476977afdae0eb5530b277f62a52b12313d50f")})
+		WriteTrustedCht(bc.chainDb, TrustedCht{Number: 1040, Root: common.HexToHash("bb4fb4076cbe6923c8a8ce8f158452bbe19564959313466989fda095a60884ca")})
 		log.Info("Added trusted CHT for mainnet")
 	}
+	if bc.genesisBlock.Hash() == params.TestnetGenesisHash {
+		// add trusted CHT
+		WriteTrustedCht(bc.chainDb, TrustedCht{Number: 400, Root: common.HexToHash("2a4befa19e4675d939c3dc22dca8c6ae9fcd642be1f04b06bd6e4203cc304660")})
+		log.Info("Added trusted CHT for ropsten testnet")
+	}
 
 	if err := bc.loadLastState(); err != nil {
 		return nil, err
@@ -252,8 +257,8 @@ func (self *LightChain) GetBodyRLP(ctx context.Context, hash common.Hash) (rlp.R
 
 // HasBlock checks if a block is fully present in the database or not, caching
 // it if present.
-func (bc *LightChain) HasBlock(hash common.Hash) bool {
-	blk, _ := bc.GetBlockByHash(NoOdr, hash)
+func (bc *LightChain) HasBlock(hash common.Hash, number uint64) bool {
+	blk, _ := bc.GetBlock(NoOdr, hash, number)
 	return blk != nil
 }
 
@@ -418,8 +423,8 @@ func (self *LightChain) GetHeaderByHash(hash common.Hash) *types.Header {
 
 // HasHeader checks if a block header is present in the database or not, caching
 // it if present.
-func (bc *LightChain) HasHeader(hash common.Hash) bool {
-	return bc.hc.HasHeader(hash)
+func (bc *LightChain) HasHeader(hash common.Hash, number uint64) bool {
+	return bc.hc.HasHeader(hash, number)
 }
 
 // GetBlockHashesFromHash retrieves a number of block hashes starting at a given
diff --git a/miner/agent.go b/miner/agent.go
index 855892a07d..e3cebbd2e2 100644
--- a/miner/agent.go
+++ b/miner/agent.go
@@ -53,7 +53,19 @@ func (self *CpuAgent) Work() chan<- *Work            { return self.workCh }
 func (self *CpuAgent) SetReturnCh(ch chan<- *Result) { self.returnCh = ch }
 
 func (self *CpuAgent) Stop() {
+	if !atomic.CompareAndSwapInt32(&self.isMining, 1, 0) {
+		return // agent already stopped
+	}
 	self.stop <- struct{}{}
+done:
+	// Empty work channel
+	for {
+		select {
+		case <-self.workCh:
+		default:
+			break done
+		}
+	}
 }
 
 func (self *CpuAgent) Start() {
@@ -85,17 +97,6 @@ out:
 			break out
 		}
 	}
-
-done:
-	// Empty work channel
-	for {
-		select {
-		case <-self.workCh:
-		default:
-			break done
-		}
-	}
-	atomic.StoreInt32(&self.isMining, 0)
 }
 
 func (self *CpuAgent) mine(work *Work, stop <-chan struct{}) {
diff --git a/miner/worker.go b/miner/worker.go
index e1154ac068..bf24970f5c 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -125,8 +125,6 @@ type worker struct {
 	// atomic status counters
 	mining int32
 	atWork int32
-
-	fullValidation bool
 }
 
 func newWorker(config *params.ChainConfig, engine consensus.Engine, coinbase common.Address, eth Backend, mux *event.TypeMux) *worker {
@@ -146,7 +144,6 @@ func newWorker(config *params.ChainConfig, engine consensus.Engine, coinbase com
 		coinbase:       coinbase,
 		agents:         make(map[Agent]struct{}),
 		unconfirmed:    newUnconfirmedBlocks(eth.BlockChain(), miningLogAtDepth),
-		fullValidation: false,
 	}
 	// Subscribe TxPreEvent for tx pool
 	worker.txSub = eth.TxPool().SubscribeTxPreEvent(worker.txCh)
@@ -268,7 +265,7 @@ func (self *worker) update() {
 				self.currentMu.Lock()
 				acc, _ := types.Sender(self.current.signer, ev.Tx)
 				txs := map[common.Address]types.Transactions{acc: {ev.Tx}}
-				txset := types.NewTransactionsByPriceAndNonce(txs)
+				txset := types.NewTransactionsByPriceAndNonce(self.current.signer, txs)
 
 				self.current.commitTransactions(self.mux, txset, self.chain, self.coinbase)
 				self.currentMu.Unlock()
@@ -297,57 +294,38 @@ func (self *worker) wait() {
 			block := result.Block
 			work := result.Work
 
-			if self.fullValidation {
-				if _, err := self.chain.InsertChain(types.Blocks{block}); err != nil {
-					log.Error("Mined invalid block", "err", err)
-					continue
+			// Update the block hash in all logs since it is now available and not when the
+			// receipt/log of individual transactions were created.
+			for _, r := range work.receipts {
+				for _, l := range r.Logs {
+					l.BlockHash = block.Hash()
 				}
-				go self.mux.Post(core.NewMinedBlockEvent{Block: block})
-			} else {
-				work.state.CommitTo(self.chainDb, self.config.IsEIP158(block.Number()))
-				stat, err := self.chain.WriteBlock(block)
-				if err != nil {
-					log.Error("Failed writing block to chain", "err", err)
-					continue
-				}
-				// update block hash since it is now available and not when the receipt/log of individual transactions were created
-				for _, r := range work.receipts {
-					for _, l := range r.Logs {
-						l.BlockHash = block.Hash()
-					}
-				}
-				for _, log := range work.state.Logs() {
-					log.BlockHash = block.Hash()
-				}
-
-				// check if canon block and write transactions
-				if stat == core.CanonStatTy {
-					// This puts transactions in a extra db for rpc
-					core.WriteTxLookupEntries(self.chainDb, block)
-					// implicit by posting ChainHeadEvent
-					mustCommitNewWork = false
-				}
-
-				// broadcast before waiting for validation
-				go func(block *types.Block, logs []*types.Log, receipts []*types.Receipt) {
-					self.mux.Post(core.NewMinedBlockEvent{Block: block})
-					var (
-						events        []interface{}
-						coalescedLogs []*types.Log
-					)
-					events = append(events, core.ChainEvent{Block: block, Hash: block.Hash(), Logs: logs})
-
-					if stat == core.CanonStatTy {
-						events = append(events, core.ChainHeadEvent{Block: block})
-						coalescedLogs = logs
-					}
-					// post blockchain events
-					self.chain.PostChainEvents(events, coalescedLogs)
-					if err := core.WriteBlockReceipts(self.chainDb, block.Hash(), block.NumberU64(), receipts); err != nil {
-						log.Warn("Failed writing block receipts", "err", err)
-					}
-				}(block, work.state.Logs(), work.receipts)
 			}
+			for _, log := range work.state.Logs() {
+				log.BlockHash = block.Hash()
+			}
+			stat, err := self.chain.WriteBlockAndState(block, work.receipts, work.state)
+			if err != nil {
+				log.Error("Failed writing block to chain", "err", err)
+				continue
+			}
+			// check if canon block and write transactions
+			if stat == core.CanonStatTy {
+				// implicit by posting ChainHeadEvent
+				mustCommitNewWork = false
+			}
+			// Broadcast the block and announce chain insertion event
+			self.mux.Post(core.NewMinedBlockEvent{Block: block})
+			var (
+				events []interface{}
+				logs   = work.state.Logs()
+			)
+			events = append(events, core.ChainEvent{Block: block, Hash: block.Hash(), Logs: logs})
+			if stat == core.CanonStatTy {
+				events = append(events, core.ChainHeadEvent{Block: block})
+			}
+			self.chain.PostChainEvents(events, logs)
+
 			// Insert the block into the set of pending ones to wait for confirmations
 			self.unconfirmed.Insert(block.NumberU64(), block.Hash())
 
@@ -471,7 +449,7 @@ func (self *worker) commitNewWork() {
 		log.Error("Failed to fetch pending transactions", "err", err)
 		return
 	}
-	txs := types.NewTransactionsByPriceAndNonce(pending)
+	txs := types.NewTransactionsByPriceAndNonce(self.current.signer, pending)
 	work.commitTransactions(self.mux, txs, self.chain, self.coinbase)
 
 	// compute uncles for the new block.
diff --git a/params/bootnodes.go b/params/bootnodes.go
index 6c6c02f8cf..82ab6d48c2 100644
--- a/params/bootnodes.go
+++ b/params/bootnodes.go
@@ -41,12 +41,14 @@ var TestnetBootnodes = []string{
 // Rinkeby test network.
 var RinkebyBootnodes = []string{
 	"enode://a24ac7c5484ef4ed0c5eb2d36620ba4e4aa13b8c84684e1b4aab0cebea2ae45cb4d375b77eab56516d34bfbd3c1a833fc51296ff084b770b94fb9028c4d25ccf@52.169.42.101:30303", // IE
+	"enode://343149e4feefa15d882d9fe4ac7d88f885bd05ebb735e547f12e12080a9fa07c8014ca6fd7f373123488102fe5e34111f8509cf0b7de3f5b44339c9f25e87cb8@52.3.158.184:30303",  // INFURA
 }
 
 // RinkebyV5Bootnodes are the enode URLs of the P2P bootstrap nodes running on the
 // Rinkeby test network for the experimental RLPx v5 topic-discovery network.
 var RinkebyV5Bootnodes = []string{
 	"enode://a24ac7c5484ef4ed0c5eb2d36620ba4e4aa13b8c84684e1b4aab0cebea2ae45cb4d375b77eab56516d34bfbd3c1a833fc51296ff084b770b94fb9028c4d25ccf@52.169.42.101:30303?discport=30304", // IE
+	"enode://343149e4feefa15d882d9fe4ac7d88f885bd05ebb735e547f12e12080a9fa07c8014ca6fd7f373123488102fe5e34111f8509cf0b7de3f5b44339c9f25e87cb8@52.3.158.184:30303?discport=30304",  // INFURA
 }
 
 // DiscoveryV5Bootnodes are the enode URLs of the P2P bootstrap nodes for the
diff --git a/params/config.go b/params/config.go
index f4bb6172ba..5c6f0b6bf7 100644
--- a/params/config.go
+++ b/params/config.go
@@ -32,45 +32,45 @@ var (
 var (
 	// MainnetChainConfig is the chain parameters to run a node on the main network.
 	MainnetChainConfig = &ChainConfig{
-		ChainId:         big.NewInt(1),
-		HomesteadBlock:  big.NewInt(1150000),
-		DAOForkBlock:    big.NewInt(1920000),
-		DAOForkSupport:  true,
-		EIP150Block:     big.NewInt(2463000),
-		EIP150Hash:      common.HexToHash("0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0"),
-		EIP155Block:     big.NewInt(2675000),
-		EIP158Block:     big.NewInt(2675000),
-		MetropolisBlock: big.NewInt(math.MaxInt64), // Don't enable yet
+		ChainId:        big.NewInt(1),
+		HomesteadBlock: big.NewInt(1150000),
+		DAOForkBlock:   big.NewInt(1920000),
+		DAOForkSupport: true,
+		EIP150Block:    big.NewInt(2463000),
+		EIP150Hash:     common.HexToHash("0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0"),
+		EIP155Block:    big.NewInt(2675000),
+		EIP158Block:    big.NewInt(2675000),
+		ByzantiumBlock: big.NewInt(math.MaxInt64), // Don't enable yet
 
 		Ethash: new(EthashConfig),
 	}
 
 	// TestnetChainConfig contains the chain parameters to run a node on the Ropsten test network.
 	TestnetChainConfig = &ChainConfig{
-		ChainId:         big.NewInt(3),
-		HomesteadBlock:  big.NewInt(0),
-		DAOForkBlock:    nil,
-		DAOForkSupport:  true,
-		EIP150Block:     big.NewInt(0),
-		EIP150Hash:      common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
-		EIP155Block:     big.NewInt(10),
-		EIP158Block:     big.NewInt(10),
-		MetropolisBlock: big.NewInt(math.MaxInt64), // Don't enable yet
+		ChainId:        big.NewInt(3),
+		HomesteadBlock: big.NewInt(0),
+		DAOForkBlock:   nil,
+		DAOForkSupport: true,
+		EIP150Block:    big.NewInt(0),
+		EIP150Hash:     common.HexToHash("0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1ca4a2d"),
+		EIP155Block:    big.NewInt(10),
+		EIP158Block:    big.NewInt(10),
+		ByzantiumBlock: big.NewInt(1700000),
 
 		Ethash: new(EthashConfig),
 	}
 
 	// RinkebyChainConfig contains the chain parameters to run a node on the Rinkeby test network.
 	RinkebyChainConfig = &ChainConfig{
-		ChainId:         big.NewInt(4),
-		HomesteadBlock:  big.NewInt(1),
-		DAOForkBlock:    nil,
-		DAOForkSupport:  true,
-		EIP150Block:     big.NewInt(2),
-		EIP150Hash:      common.HexToHash("0x9b095b36c15eaf13044373aef8ee0bd3a382a5abb92e402afa44b8249c3a90e9"),
-		EIP155Block:     big.NewInt(3),
-		EIP158Block:     big.NewInt(3),
-		MetropolisBlock: big.NewInt(math.MaxInt64), // Don't enable yet
+		ChainId:        big.NewInt(4),
+		HomesteadBlock: big.NewInt(1),
+		DAOForkBlock:   nil,
+		DAOForkSupport: true,
+		EIP150Block:    big.NewInt(2),
+		EIP150Hash:     common.HexToHash("0x9b095b36c15eaf13044373aef8ee0bd3a382a5abb92e402afa44b8249c3a90e9"),
+		EIP155Block:    big.NewInt(3),
+		EIP158Block:    big.NewInt(3),
+		ByzantiumBlock: big.NewInt(math.MaxInt64), // Don't enable yet
 
 		Clique: &CliqueConfig{
 			Period: 15,
@@ -86,8 +86,8 @@ var (
 	// means that all fields must be set at all times. This forces
 	// anyone adding flags to the config to also have to set these
 	// fields.
-	AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(math.MaxInt64) /*disabled*/, new(EthashConfig), nil}
-	TestChainConfig    = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), nil, new(EthashConfig), nil}
+	AllProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), new(EthashConfig), nil}
+	TestChainConfig    = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), new(EthashConfig), nil}
 	TestRules          = TestChainConfig.Rules(new(big.Int))
 )
 
@@ -110,7 +110,7 @@ type ChainConfig struct {
 	EIP155Block *big.Int `json:"eip155Block,omitempty"` // EIP155 HF block
 	EIP158Block *big.Int `json:"eip158Block,omitempty"` // EIP158 HF block
 
-	MetropolisBlock *big.Int `json:"metropolisBlock,omitempty"` // Metropolis switch block (nil = no fork, 0 = alraedy on homestead)
+	ByzantiumBlock *big.Int `json:"byzantiumBlock,omitempty"` // Byzantium switch block (nil = no fork, 0 = alraedy on homestead)
 
 	// Various consensus engines
 	Ethash *EthashConfig `json:"ethash,omitempty"`
@@ -147,7 +147,7 @@ func (c *ChainConfig) String() string {
 	default:
 		engine = "unknown"
 	}
-	return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Metropolis: %v Engine: %v}",
+	return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Byzantium: %v Engine: %v}",
 		c.ChainId,
 		c.HomesteadBlock,
 		c.DAOForkBlock,
@@ -155,7 +155,7 @@ func (c *ChainConfig) String() string {
 		c.EIP150Block,
 		c.EIP155Block,
 		c.EIP158Block,
-		c.MetropolisBlock,
+		c.ByzantiumBlock,
 		engine,
 	)
 }
@@ -182,8 +182,8 @@ func (c *ChainConfig) IsEIP158(num *big.Int) bool {
 	return isForked(c.EIP158Block, num)
 }
 
-func (c *ChainConfig) IsMetropolis(num *big.Int) bool {
-	return isForked(c.MetropolisBlock, num)
+func (c *ChainConfig) IsByzantium(num *big.Int) bool {
+	return isForked(c.ByzantiumBlock, num)
 }
 
 // GasTable returns the gas table corresponding to the current phase (homestead or homestead reprice).
@@ -243,8 +243,8 @@ func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, head *big.Int) *Confi
 	if c.IsEIP158(head) && !configNumEqual(c.ChainId, newcfg.ChainId) {
 		return newCompatError("EIP158 chain ID", c.EIP158Block, newcfg.EIP158Block)
 	}
-	if isForkIncompatible(c.MetropolisBlock, newcfg.MetropolisBlock, head) {
-		return newCompatError("Metropolis fork block", c.MetropolisBlock, newcfg.MetropolisBlock)
+	if isForkIncompatible(c.ByzantiumBlock, newcfg.ByzantiumBlock, head) {
+		return newCompatError("Byzantium fork block", c.ByzantiumBlock, newcfg.ByzantiumBlock)
 	}
 	return nil
 }
@@ -312,7 +312,7 @@ func (err *ConfigCompatError) Error() string {
 type Rules struct {
 	ChainId                                   *big.Int
 	IsHomestead, IsEIP150, IsEIP155, IsEIP158 bool
-	IsMetropolis                              bool
+	IsByzantium                               bool
 }
 
 func (c *ChainConfig) Rules(num *big.Int) Rules {
@@ -320,5 +320,5 @@ func (c *ChainConfig) Rules(num *big.Int) Rules {
 	if chainId == nil {
 		chainId = new(big.Int)
 	}
-	return Rules{ChainId: new(big.Int).Set(chainId), IsHomestead: c.IsHomestead(num), IsEIP150: c.IsEIP150(num), IsEIP155: c.IsEIP155(num), IsEIP158: c.IsEIP158(num), IsMetropolis: c.IsMetropolis(num)}
+	return Rules{ChainId: new(big.Int).Set(chainId), IsHomestead: c.IsHomestead(num), IsEIP150: c.IsEIP150(num), IsEIP155: c.IsEIP155(num), IsEIP158: c.IsEIP158(num), IsByzantium: c.IsByzantium(num)}
 }
diff --git a/params/protocol_params.go b/params/protocol_params.go
index 9c84c7d348..c56faf56f8 100644
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -64,9 +64,9 @@ const (
 	Ripemd160PerWordGas     uint64 = 120    // Per-word price for a RIPEMD160 operation
 	IdentityBaseGas         uint64 = 15     // Base price for a data copy operation
 	IdentityPerWordGas      uint64 = 3      // Per-work price for a data copy operation
-	ModExpQuadCoeffDiv      uint64 = 100    // Divisor for the quadratic particle of the big int modular exponentiation
+	ModExpQuadCoeffDiv      uint64 = 20     // Divisor for the quadratic particle of the big int modular exponentiation
 	Bn256AddGas             uint64 = 500    // Gas needed for an elliptic curve addition
-	Bn256ScalarMulGas       uint64 = 2000   // Gas needed for an elliptic curve scalar multiplication
+	Bn256ScalarMulGas       uint64 = 40000  // Gas needed for an elliptic curve scalar multiplication
 	Bn256PairingBaseGas     uint64 = 100000 // Base price for an elliptic curve pairing check
 	Bn256PairingPerPointGas uint64 = 80000  // Per-point price for an elliptic curve pairing check
 )
diff --git a/params/version.go b/params/version.go
index 0896662606..80329c91d9 100644
--- a/params/version.go
+++ b/params/version.go
@@ -23,7 +23,7 @@ import (
 const (
 	VersionMajor = 1          // Major version component of the current release
 	VersionMinor = 7          // Minor version component of the current release
-	VersionPatch = 0          // Patch version component of the current release
+	VersionPatch = 1          // Patch version component of the current release
 	VersionMeta  = "unstable" // Version metadata to append to the version string
 )
 
diff --git a/swarm/api/api.go b/swarm/api/api.go
index 7d185ab3ca..a5941fb5cd 100644
--- a/swarm/api/api.go
+++ b/swarm/api/api.go
@@ -132,6 +132,7 @@ func (self *Api) Put(content, contentType string) (storage.Key, error) {
 func (self *Api) Get(key storage.Key, path string) (reader storage.LazySectionReader, mimeType string, status int, err error) {
 	trie, err := loadManifest(self.dpa, key, nil)
 	if err != nil {
+		status = http.StatusNotFound
 		log.Warn(fmt.Sprintf("loadManifestTrie error: %v", err))
 		return
 	}
diff --git a/swarm/api/http/error.go b/swarm/api/http/error.go
new file mode 100644
index 0000000000..ebb5e3ebe2
--- /dev/null
+++ b/swarm/api/http/error.go
@@ -0,0 +1,116 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+Show nicely (but simple) formatted HTML error pages (or respond with JSON
+if the appropriate `Accept` header is set)) for the http package.
+*/
+package http
+
+import (
+	"encoding/json"
+	"fmt"
+	"html/template"
+	"net/http"
+	"time"
+
+	"github.com/ethereum/go-ethereum/log"
+)
+
+//templateMap holds a mapping of an HTTP error code to a template
+var templateMap map[int]*template.Template
+
+//parameters needed for formatting the correct HTML page
+type ErrorParams struct {
+	Msg       string
+	Code      int
+	Timestamp string
+	template  *template.Template
+	Details   template.HTML
+}
+
+//we init the error handling right on boot time, so lookup and http response is fast
+func init() {
+	initErrHandling()
+}
+
+func initErrHandling() {
+	//pages are saved as strings - get these strings
+	genErrPage := GetGenericErrorPage()
+	notFoundPage := GetNotFoundErrorPage()
+	//map the codes to the available pages
+	tnames := map[int]string{
+		0:   genErrPage, //default
+		400: genErrPage,
+		404: notFoundPage,
+		500: genErrPage,
+	}
+	templateMap = make(map[int]*template.Template)
+	for code, tname := range tnames {
+		//assign formatted HTML to the code
+		templateMap[code] = template.Must(template.New(fmt.Sprintf("%d", code)).Parse(tname))
+	}
+}
+
+//ShowError is used to show an HTML error page to a client.
+//If there is an `Accept` header of `application/json`, JSON will be returned instead
+//The function just takes a string message which will be displayed in the error page.
+//The code is used to evaluate which template will be displayed
+//(and return the correct HTTP status code)
+func ShowError(w http.ResponseWriter, r *http.Request, msg string, code int) {
+	if code == http.StatusInternalServerError {
+		log.Error(msg)
+	}
+	respond(w, r, &ErrorParams{
+		Code:      code,
+		Msg:       msg,
+		Timestamp: time.Now().Format(time.RFC1123),
+		template:  getTemplate(code),
+	})
+}
+
+//evaluate if client accepts html or json response
+func respond(w http.ResponseWriter, r *http.Request, params *ErrorParams) {
+	w.WriteHeader(params.Code)
+	if r.Header.Get("Accept") == "application/json" {
+		respondJson(w, params)
+	} else {
+		respondHtml(w, params)
+	}
+}
+
+//return a HTML page
+func respondHtml(w http.ResponseWriter, params *ErrorParams) {
+	err := params.template.Execute(w, params)
+	if err != nil {
+		log.Error(err.Error())
+	}
+}
+
+//return JSON
+func respondJson(w http.ResponseWriter, params *ErrorParams) {
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(params)
+}
+
+//get the HTML template for a given code
+func getTemplate(code int) *template.Template {
+	if val, tmpl := templateMap[code]; tmpl {
+		return val
+	} else {
+		return templateMap[0]
+	}
+}
diff --git a/swarm/api/http/error_templates.go b/swarm/api/http/error_templates.go
new file mode 100644
index 0000000000..29bd3bfbb1
--- /dev/null
+++ b/swarm/api/http/error_templates.go
@@ -0,0 +1,376 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+We use html templates to handle simple but as informative as possible error pages.
+
+To eliminate circular dependency in case of an error, we don't store error pages on swarm.
+We can't save the error pages as html files on disk, or when deploying compiled binaries
+they won't be found.
+
+For this reason we resort to save the HTML error pages as strings, which then can be
+parsed by Go's html/template package
+*/
+package http
+
+//This returns the HTML for generic errors
+func GetGenericErrorPage() string {
+	page := `
+<html>
+
+  <head>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
+    <meta http-equiv="X-UA-Compatible" ww="chrome=1">
+    <meta name="description" content="Ethereum/Swarm error page">
+    <meta property="og:url" content="https://swarm-gateways.net/bzz:/theswarm.eth">
+
+    <style>
+
+      body, div, header, footer {
+        margin: 0;
+        padding: 0;
+      }
+
+      body {
+        overflow: hidden;
+      }
+
+      .container {
+        min-width: 100%;
+        min-height: 100%;
+        max-height: 100%;
+      }
+
+      header {
+        display: flex;
+        align-items: center;
+        background-color: #ffa500;
+        /* height: 20vh; */
+        padding: 5px;
+      }
+
+      .header-left, .header-right {
+        width: 20%;
+      }
+
+      .header-left {
+        padding-left: 40px;
+        float: left;
+      }
+
+      .header-right {
+        padding-right: 40px;
+        float: right;
+      }
+
+      .page-title {
+        /* margin-top: 4.5vh; */
+        text-align: center;
+        float:      left;
+        width:      60%;
+        color:      white;
+      }
+
+      content-body {
+        display: block;
+        margin: 0 auto;
+        /* width: 50%; */
+        min-height: 60vh; 
+        max-height: 60vh; 
+        padding: 50px 20px;
+        opacity: 0.6;
+        background-color: #A9F5BF;
+      }
+
+      table {
+        font-size: 1.2em;
+        margin: 0 auto;
+      }
+
+      tr {
+        height: 60px;
+      }
+
+      td {
+        text-align: center;
+      }
+
+      .key {
+        color: #111;
+        font-weight: bold;
+        width: 200px;
+      }
+
+      .value {
+        color: red;
+        font-weight: bold
+      }
+
+      footer {
+        height: 20vh;
+        background-color: #ffa500;
+        font-size: 1em;
+        text-align: center;
+        padding: 20px;
+      }
+
+    </style>
+
+    <title>Swarm::HTTP Error Page</title>
+  </head>
+
+
+  <body>
+    <div class="container">
+
+      <header>
+        <div class="header-left">
+          <img style="height:18vh;margin-left:40px" src="data:image/png;base64,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"/>
+        </div>
+        <div class="page-title">
+          <h1>There was a problem serving the requested page</h1>
+        </div>
+        <div class="header-right">
+          <div id="timestamp">{{.Timestamp}}</div>
+        </div>
+      </header>
+
+      <content-body>
+        <section>
+          <table>
+            <thead>
+              <td style="height: 150px; font-size: 1.3em; color: black; font-weight: bold">
+                Hmmmmm....Swarm was not able to serve your request!
+              </td>
+            </thead>
+            <tbody>
+              <tr>
+                <td class="key">
+                  Error message:
+                </td>
+              </tr>
+              <tr>
+                <td class="value">
+                  {{.Msg}}                 
+                </td>
+              </tr>
+
+              <tr>
+                <td class="key">
+                  Error code:
+                </td>
+              </tr>
+              <tr>
+                <td class="value">
+                  {{.Code}}
+                </td>
+              </tr>
+
+            </tbody>
+          </table>
+        </section>
+      </content-body>
+
+      <footer>
+        <p>
+          Swarm: Serverless Hosting Incentivised Peer-To-Peer Storage And Content Distribution<br/>
+          <a href="http://swarm-gateways.net/bzz:/theswarm.eth">Swarm</a>
+        </p>
+      </footer>
+
+
+    </div>
+  </body>
+
+</html>
+`
+	return page
+}
+
+//This returns the HTML for a 404 Not Found error
+func GetNotFoundErrorPage() string {
+	page := `
+<html>
+
+  <head>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
+    <meta http-equiv="X-UA-Compatible" ww="chrome=1">
+    <meta name="description" content="Ethereum/Swarm error page">
+    <meta property="og:url" content="https://swarm-gateways.net/bzz:/theswarm.eth">
+
+    <style>
+
+      body, div, header, footer {
+        margin: 0;
+        padding: 0;
+      }
+
+      body {
+        overflow: hidden;
+      }
+
+      .container {
+        min-width: 100%;
+        min-height: 100%;
+        max-height: 100%;
+      }
+
+      header {
+        display: flex;
+        align-items: center;
+        background-color: #ffa500;
+        /* height: 20vh; */
+        padding: 5px;
+      }
+
+      .header-left, .header-right {
+        width: 20%;
+      }
+
+      .header-left {
+        padding-left: 40px;
+        float: left;
+      }
+
+      .header-right {
+        padding-right: 40px;
+        float: right;
+      }
+
+      .page-title {
+        /* margin-top: 4.5vh; */
+        text-align: center;
+        float:      left;
+        width:      60%;
+        color:      white;
+      }
+
+      content-body {
+        display: block;
+        margin: 0 auto;
+        /* width: 50%; */
+        min-height: 60vh; 
+        max-height: 60vh; 
+        padding: 50px 20px;
+        opacity: 0.6;
+        background-color: #A9F5BF;
+      }
+
+      table {
+        font-size: 1.2em;
+        margin: 0 auto;
+      }
+
+      tr {
+        height: 60px;
+      }
+
+      td {
+        text-align: center;
+      }
+
+      .key {
+        color: #111;
+        font-weight: bold;
+        width: 200px;
+      }
+
+      .value {
+        color: red;
+        font-weight: bold
+      }
+
+      footer {
+        height: 20vh;
+        background-color: #ffa500;
+        font-size: 1em;
+        text-align: center;
+        padding: 20px;
+      }
+
+    </style>
+
+    <title>Swarm::404 HTTP Not Found</title>
+  </head>
+
+
+  <body>
+    <div class="container">
+
+      <header>
+        <div class="header-left">
+          <img style="height:18vh;margin-left:40px" src="data:image/png;base64,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"/>
+        </div>
+        <div class="page-title">
+          <h1>Resource Not Found</h1>
+        </div>
+        <div class="header-right">
+          <div id="timestamp">{{.Timestamp}}</div>
+        </div>
+      </header>
+
+      <content-body>
+        <section>
+          <table>
+            <thead>
+              <td style="height: 150px; font-size: 1.3em; color: black; font-weight: bold">
+                Unfortunately, the resource you were trying to access could not be found on swarm. 
+              </td>
+            </thead>
+            <tbody>
+              <tr>
+                <td class="key">
+                </td>
+              </tr>
+              <tr>
+                <td class="value">
+                  {{.Msg}}                 
+                </td>
+              </tr>
+
+              <tr>
+                <td class="key">
+                  Error code:
+                </td>
+              </tr>
+              <tr>
+                <td class="value">
+                  {{.Code}}
+                </td>
+              </tr>
+
+            </tbody>
+          </table>
+        </section>
+      </content-body>
+
+      <footer>
+        <p>
+          Swarm: Serverless Hosting Incentivised Peer-To-Peer Storage And Content Distribution<br/>
+          <a href="http://swarm-gateways.net/bzz:/theswarm.eth">Swarm</a>
+        </p>
+      </footer>
+
+
+    </div>
+  </body>
+
+</html>
+`
+	return page
+}
diff --git a/swarm/api/http/error_test.go b/swarm/api/http/error_test.go
new file mode 100644
index 0000000000..465fbf4cad
--- /dev/null
+++ b/swarm/api/http/error_test.go
@@ -0,0 +1,143 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package http_test
+
+import (
+	"encoding/json"
+	"golang.org/x/net/html"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/swarm/testutil"
+)
+
+func TestError(t *testing.T) {
+
+	srv := testutil.NewTestSwarmServer(t)
+	defer srv.Close()
+
+	var resp *http.Response
+	var respbody []byte
+
+	url := srv.URL + "/this_should_fail_as_no_bzz_protocol_present"
+	resp, err := http.Get(url)
+
+	if err != nil {
+		t.Fatalf("Request failed: %v", err)
+	}
+	defer resp.Body.Close()
+	respbody, err = ioutil.ReadAll(resp.Body)
+
+	if resp.StatusCode != 400 && !strings.Contains(string(respbody), "Invalid URI &#34;/this_should_fail_as_no_bzz_protocol_present&#34;: unknown scheme") {
+		t.Fatalf("Response body does not match, expected: %v, to contain: %v; received code %d, expected code: %d", string(respbody), "Invalid bzz URI: unknown scheme", 400, resp.StatusCode)
+	}
+
+	_, err = html.Parse(strings.NewReader(string(respbody)))
+	if err != nil {
+		t.Fatalf("HTML validation failed for error page returned!")
+	}
+}
+
+func Test404Page(t *testing.T) {
+	srv := testutil.NewTestSwarmServer(t)
+	defer srv.Close()
+
+	var resp *http.Response
+	var respbody []byte
+
+	url := srv.URL + "/bzz:/1234567890123456789012345678901234567890123456789012345678901234"
+	resp, err := http.Get(url)
+
+	if err != nil {
+		t.Fatalf("Request failed: %v", err)
+	}
+	defer resp.Body.Close()
+	respbody, err = ioutil.ReadAll(resp.Body)
+
+	if resp.StatusCode != 404 || !strings.Contains(string(respbody), "404") {
+		t.Fatalf("Invalid Status Code received, expected 404, got %d", resp.StatusCode)
+	}
+
+	_, err = html.Parse(strings.NewReader(string(respbody)))
+	if err != nil {
+		t.Fatalf("HTML validation failed for error page returned!")
+	}
+}
+
+func Test500Page(t *testing.T) {
+	srv := testutil.NewTestSwarmServer(t)
+	defer srv.Close()
+
+	var resp *http.Response
+	var respbody []byte
+
+	url := srv.URL + "/bzz:/thisShouldFailWith500Code"
+	resp, err := http.Get(url)
+
+	if err != nil {
+		t.Fatalf("Request failed: %v", err)
+	}
+	defer resp.Body.Close()
+	respbody, err = ioutil.ReadAll(resp.Body)
+
+	if resp.StatusCode != 500 || !strings.Contains(string(respbody), "500") {
+		t.Fatalf("Invalid Status Code received, expected 500, got %d", resp.StatusCode)
+	}
+
+	_, err = html.Parse(strings.NewReader(string(respbody)))
+	if err != nil {
+		t.Fatalf("HTML validation failed for error page returned!")
+	}
+}
+
+func TestJsonResponse(t *testing.T) {
+	srv := testutil.NewTestSwarmServer(t)
+	defer srv.Close()
+
+	var resp *http.Response
+	var respbody []byte
+
+	url := srv.URL + "/bzz:/thisShouldFailWith500Code/"
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		t.Fatalf("Request failed: %v", err)
+	}
+	req.Header.Set("Accept", "application/json")
+	resp, err = http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("Request failed: %v", err)
+	}
+
+	defer resp.Body.Close()
+	respbody, err = ioutil.ReadAll(resp.Body)
+
+	if resp.StatusCode != 500 {
+		t.Fatalf("Invalid Status Code received, expected 500, got %d", resp.StatusCode)
+	}
+
+	if !isJSON(string(respbody)) {
+		t.Fatalf("Expected repsonse to be JSON, received invalid JSON: %s", string(respbody))
+	}
+
+}
+
+func isJSON(s string) bool {
+	var js map[string]interface{}
+	return json.Unmarshal([]byte(s), &js) == nil
+}
diff --git a/swarm/api/http/server.go b/swarm/api/http/server.go
index 0b4ec7e18e..a637b87351 100644
--- a/swarm/api/http/server.go
+++ b/swarm/api/http/server.go
@@ -332,7 +332,7 @@ func (s *Server) HandleGetRaw(w http.ResponseWriter, r *Request) {
 			return api.SkipManifest
 		})
 		if entry == nil {
-			http.NotFound(w, &r.Request)
+			s.NotFound(w, r, fmt.Errorf("Manifest entry could not be loaded"))
 			return
 		}
 		key = storage.Key(common.Hex2Bytes(entry.Hash))
@@ -341,8 +341,7 @@ func (s *Server) HandleGetRaw(w http.ResponseWriter, r *Request) {
 	// check the root chunk exists by retrieving the file's size
 	reader := s.api.Retrieve(key)
 	if _, err := reader.Size(nil); err != nil {
-		s.logDebug("key not found %s: %s", key, err)
-		http.NotFound(w, &r.Request)
+		s.NotFound(w, r, fmt.Errorf("Root chunk not found %s: %s", key, err))
 		return
 	}
 
@@ -534,16 +533,20 @@ func (s *Server) HandleGetFile(w http.ResponseWriter, r *Request) {
 		return
 	}
 
-	reader, contentType, _, err := s.api.Get(key, r.uri.Path)
+	reader, contentType, status, err := s.api.Get(key, r.uri.Path)
 	if err != nil {
-		s.Error(w, r, err)
+		switch status {
+		case http.StatusNotFound:
+			s.NotFound(w, r, err)
+		default:
+			s.Error(w, r, err)
+		}
 		return
 	}
 
 	// check the root chunk exists by retrieving the file's size
 	if _, err := reader.Size(nil); err != nil {
-		s.logDebug("file not found %s: %s", r.uri, err)
-		http.NotFound(w, &r.Request)
+		s.NotFound(w, r, fmt.Errorf("File not found %s: %s", r.uri, err))
 		return
 	}
 
@@ -556,14 +559,14 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	s.logDebug("HTTP %s request URL: '%s', Host: '%s', Path: '%s', Referer: '%s', Accept: '%s'", r.Method, r.RequestURI, r.URL.Host, r.URL.Path, r.Referer(), r.Header.Get("Accept"))
 
 	uri, err := api.Parse(strings.TrimLeft(r.URL.Path, "/"))
+	req := &Request{Request: *r, uri: uri}
 	if err != nil {
 		s.logError("Invalid URI %q: %s", r.URL.Path, err)
-		http.Error(w, fmt.Sprintf("Invalid bzz URI: %s", err), http.StatusBadRequest)
+		s.BadRequest(w, req, fmt.Sprintf("Invalid URI %q: %s", r.URL.Path, err))
 		return
 	}
 	s.logDebug("%s request received for %s", r.Method, uri)
 
-	req := &Request{Request: *r, uri: uri}
 	switch r.Method {
 	case "POST":
 		if uri.Raw() {
@@ -579,7 +582,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		//   strictly a traditional PUT request which replaces content
 		//   at a URI, and POST is more ubiquitous)
 		if uri.Raw() {
-			http.Error(w, fmt.Sprintf("No PUT to %s allowed.", uri), http.StatusBadRequest)
+			ShowError(w, r, fmt.Sprintf("No PUT to %s allowed.", uri), http.StatusBadRequest)
 			return
 		} else {
 			s.HandlePostFiles(w, req)
@@ -587,7 +590,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	case "DELETE":
 		if uri.Raw() {
-			http.Error(w, fmt.Sprintf("No DELETE to %s allowed.", uri), http.StatusBadRequest)
+			ShowError(w, r, fmt.Sprintf("No DELETE to %s allowed.", uri), http.StatusBadRequest)
 			return
 		}
 		s.HandleDelete(w, req)
@@ -611,7 +614,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		s.HandleGetFile(w, req)
 
 	default:
-		http.Error(w, "Method "+r.Method+" is not supported.", http.StatusMethodNotAllowed)
+		ShowError(w, r, fmt.Sprintf("Method "+r.Method+" is not supported.", uri), http.StatusMethodNotAllowed)
 
 	}
 }
@@ -643,11 +646,13 @@ func (s *Server) logError(format string, v ...interface{}) {
 }
 
 func (s *Server) BadRequest(w http.ResponseWriter, r *Request, reason string) {
-	s.logDebug("bad request %s %s: %s", r.Method, r.uri, reason)
-	http.Error(w, reason, http.StatusBadRequest)
+	ShowError(w, &r.Request, fmt.Sprintf("Bad request %s %s: %s", r.Method, r.uri, reason), http.StatusBadRequest)
 }
 
 func (s *Server) Error(w http.ResponseWriter, r *Request, err error) {
-	s.logError("error serving %s %s: %s", r.Method, r.uri, err)
-	http.Error(w, err.Error(), http.StatusInternalServerError)
+	ShowError(w, &r.Request, fmt.Sprintf("Error serving %s %s: %s", r.Method, r.uri, err), http.StatusInternalServerError)
+}
+
+func (s *Server) NotFound(w http.ResponseWriter, r *Request, err error) {
+	ShowError(w, &r.Request, fmt.Sprintf("NOT FOUND error serving %s %s: %s", r.Method, r.uri, err), http.StatusNotFound)
 }
diff --git a/swarm/api/http/server_test.go b/swarm/api/http/server_test.go
index d3374594b6..ffeaf6e0d8 100644
--- a/swarm/api/http/server_test.go
+++ b/swarm/api/http/server_test.go
@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"strings"
 	"sync"
 	"testing"
 
@@ -110,9 +111,9 @@ func TestBzzrGetPath(t *testing.T) {
 	}
 
 	nonhashresponses := []string{
-		"error resolving name: no DNS to resolve name: \"name\"\n",
-		"error resolving nonhash: immutable address not a content hash: \"nonhash\"\n",
-		"error resolving nonhash: no DNS to resolve name: \"nonhash\"\n",
+		"error resolving name: no DNS to resolve name: &#34;name&#34;",
+		"error resolving nonhash: immutable address not a content hash: &#34;nonhash&#34;",
+		"error resolving nonhash: no DNS to resolve name: &#34;nonhash&#34;",
 	}
 
 	for i, url := range nonhashtests {
@@ -129,7 +130,7 @@ func TestBzzrGetPath(t *testing.T) {
 		if err != nil {
 			t.Fatalf("ReadAll failed: %v", err)
 		}
-		if string(respbody) != nonhashresponses[i] {
+		if !strings.Contains(string(respbody), nonhashresponses[i]) {
 			t.Fatalf("Non-Hash response body does not match, expected: %v, got: %v", nonhashresponses[i], string(respbody))
 		}
 	}
diff --git a/swarm/fuse/swarmfs_test.go b/swarm/fuse/swarmfs_test.go
index 69f3cc6157..93f1d4c2fd 100644
--- a/swarm/fuse/swarmfs_test.go
+++ b/swarm/fuse/swarmfs_test.go
@@ -140,7 +140,7 @@ func compareGeneratedFileWithFileInMount(t *testing.T, files map[string]fileInfo
 		if err != nil {
 			t.Fatalf("Could not readfile %v : %v", fname, err)
 		}
-		if bytes.Compare(fileContents, finfo.contents) != 0 {
+		if !bytes.Equal(fileContents, finfo.contents) {
 			t.Fatalf("File %v contents mismatch: %v , %v", fname, fileContents, finfo.contents)
 
 		}
diff --git a/tests/block_test.go b/tests/block_test.go
index 56e1e1e8da..669d3ca08a 100644
--- a/tests/block_test.go
+++ b/tests/block_test.go
@@ -32,8 +32,6 @@ func TestBlockchain(t *testing.T) {
 	bt.skipLoad(`^bcTotalDifficultyTest/(lotsOfLeafs|lotsOfBranches|sideChainWithMoreTransactions)`)
 	// Constantinople is not implemented yet.
 	bt.skipLoad(`(?i)(constantinople)`)
-	// Expected failures:
-	bt.fails(`^TransitionTests/bcHomesteadToDao/DaoTransactions(|_UncleExtradata|_EmptyTransactionAndForkBlocksAhead)\.json`, "issue in test")
 
 	// Still failing tests
 	bt.skipLoad(`^bcWalletTest.*_Byzantium$`)
diff --git a/tests/init.go b/tests/init.go
index 0c3fe61d13..a2c633ad67 100644
--- a/tests/init.go
+++ b/tests/init.go
@@ -45,13 +45,13 @@ var Forks = map[string]*params.ChainConfig{
 		EIP158Block:    big.NewInt(0),
 	},
 	"Byzantium": &params.ChainConfig{
-		ChainId:         big.NewInt(1),
-		HomesteadBlock:  big.NewInt(0),
-		EIP150Block:     big.NewInt(0),
-		EIP155Block:     big.NewInt(0),
-		EIP158Block:     big.NewInt(0),
-		DAOForkBlock:    big.NewInt(0),
-		MetropolisBlock: big.NewInt(0),
+		ChainId:        big.NewInt(1),
+		HomesteadBlock: big.NewInt(0),
+		EIP150Block:    big.NewInt(0),
+		EIP155Block:    big.NewInt(0),
+		EIP158Block:    big.NewInt(0),
+		DAOForkBlock:   big.NewInt(0),
+		ByzantiumBlock: big.NewInt(0),
 	},
 	"FrontierToHomesteadAt5": &params.ChainConfig{
 		ChainId:        big.NewInt(1),
@@ -69,12 +69,12 @@ var Forks = map[string]*params.ChainConfig{
 		DAOForkSupport: true,
 	},
 	"EIP158ToByzantiumAt5": &params.ChainConfig{
-		ChainId:         big.NewInt(1),
-		HomesteadBlock:  big.NewInt(0),
-		EIP150Block:     big.NewInt(0),
-		EIP155Block:     big.NewInt(0),
-		EIP158Block:     big.NewInt(0),
-		MetropolisBlock: big.NewInt(5),
+		ChainId:        big.NewInt(1),
+		HomesteadBlock: big.NewInt(0),
+		EIP150Block:    big.NewInt(0),
+		EIP155Block:    big.NewInt(0),
+		EIP158Block:    big.NewInt(0),
+		ByzantiumBlock: big.NewInt(5),
 	},
 }
 
diff --git a/tests/state_test.go b/tests/state_test.go
index 1fb7f5908f..9a7430fbeb 100644
--- a/tests/state_test.go
+++ b/tests/state_test.go
@@ -39,6 +39,13 @@ func TestState(t *testing.T) {
 	st.fails(`^stRevertTest/RevertPrefoundEmptyOOG\.json/EIP158`, "bug in test")
 	st.fails(`^stRevertTest/RevertPrecompiledTouch\.json/Byzantium`, "bug in test")
 	st.fails(`^stRevertTest/RevertPrefoundEmptyOOG\.json/Byzantium`, "bug in test")
+	st.fails( `^stRandom/randomStatetest645\.json/EIP150/.*`, "known bug #15119")
+	st.fails( `^stRandom/randomStatetest645\.json/Frontier/.*`, "known bug #15119")
+	st.fails( `^stRandom/randomStatetest645\.json/Homestead/.*`, "known bug #15119")
+	st.fails( `^stRandom/randomStatetest644\.json/EIP150/.*`, "known bug #15119")
+	st.fails( `^stRandom/randomStatetest644\.json/Frontier/.*`, "known bug #15119")
+	st.fails( `^stRandom/randomStatetest644\.json/Homestead/.*`, "known bug #15119")
+
 
 	st.walk(t, stateTestDir, func(t *testing.T, name string, test *StateTest) {
 		for _, subtest := range test.Subtests() {
@@ -59,7 +66,8 @@ func TestState(t *testing.T) {
 }
 
 // Transactions with gasLimit above this value will not get a VM trace on failure.
-const traceErrorLimit = 400000
+//const traceErrorLimit = 400000
+const traceErrorLimit = 0
 
 func withTrace(t *testing.T, gasLimit uint64, test func(vm.Config) error) {
 	err := test(vm.Config{})
diff --git a/tests/testdata b/tests/testdata
index 1d30b47956..ca41e90635 160000
--- a/tests/testdata
+++ b/tests/testdata
@@ -1 +1 @@
-Subproject commit 1d30b4795664f64b1b157971754e14a10cfd9115
+Subproject commit ca41e906351209481bce3a1b35501f25a79023c5
diff --git a/tests/transaction_test.go b/tests/transaction_test.go
index 72d43c0ece..c743996c2a 100644
--- a/tests/transaction_test.go
+++ b/tests/transaction_test.go
@@ -37,12 +37,12 @@ func TestTransaction(t *testing.T) {
 		EIP158Block:    big.NewInt(0),
 		ChainId:        big.NewInt(1),
 	})
-	txt.config(`^Metropolis/`, params.ChainConfig{
-		HomesteadBlock:  big.NewInt(0),
-		EIP150Block:     big.NewInt(0),
-		EIP155Block:     big.NewInt(0),
-		EIP158Block:     big.NewInt(0),
-		MetropolisBlock: big.NewInt(0),
+	txt.config(`^Byzantium/`, params.ChainConfig{
+		HomesteadBlock: big.NewInt(0),
+		EIP150Block:    big.NewInt(0),
+		EIP155Block:    big.NewInt(0),
+		EIP158Block:    big.NewInt(0),
+		ByzantiumBlock: big.NewInt(0),
 	})
 
 	txt.walk(t, transactionTestDir, func(t *testing.T, name string, test *TransactionTest) {
diff --git a/trie/hasher.go b/trie/hasher.go
index 672456e2d9..4719aabf62 100644
--- a/trie/hasher.go
+++ b/trie/hasher.go
@@ -76,7 +76,7 @@ func (h *hasher) hash(n node, db DatabaseWriter, force bool) (node, node, error)
 	if err != nil {
 		return hashNode{}, n, err
 	}
-	// Cache the hash of the ndoe for later reuse and remove
+	// Cache the hash of the node for later reuse and remove
 	// the dirty flag in commit mode. It's fine to assign these values directly
 	// without copying the node first because hashChildren copies it.
 	cachedHash, _ := hashed.(hashNode)
diff --git a/trie/sync.go b/trie/sync.go
index 1e4f8d87c1..fea10051f4 100644
--- a/trie/sync.go
+++ b/trie/sync.go
@@ -138,7 +138,7 @@ func (s *TrieSync) AddRawEntry(hash common.Hash, depth int, parent common.Hash)
 	if _, ok := s.membatch.batch[hash]; ok {
 		return
 	}
-	if blob, _ := s.database.Get(hash.Bytes()); blob != nil {
+	if ok, _ := s.database.Has(hash.Bytes()); ok {
 		return
 	}
 	// Assemble the new sub-trie sync request
@@ -296,8 +296,7 @@ func (s *TrieSync) children(req *request, object node) ([]*request, error) {
 			if _, ok := s.membatch.batch[hash]; ok {
 				continue
 			}
-			blob, _ := s.database.Get(node)
-			if local, err := decodeNode(node[:], blob, 0); local != nil && err == nil {
+			if ok, _ := s.database.Has(node); ok {
 				continue
 			}
 			// Locally unknown node, schedule for retrieval
diff --git a/trie/trie.go b/trie/trie.go
index a3151b1ce7..7f69a3d1de 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -66,6 +66,7 @@ type Database interface {
 // DatabaseReader wraps the Get method of a backing store for the trie.
 type DatabaseReader interface {
 	Get(key []byte) (value []byte, err error)
+	Has(key []byte) (bool, error)
 }
 
 // DatabaseWriter wraps the Put method of a backing store for the trie.