diff --git a/whisper/whisperv5/api.go b/whisper/whisperv5/api.go
index a93ac9baf1..e51d2ed1e4 100644
--- a/whisper/whisperv5/api.go
+++ b/whisper/whisperv5/api.go
@@ -138,18 +138,6 @@ func (api *PublicWhisperAPI) GetPublicKey(id string) (hexutil.Bytes, error) {
 	return crypto.FromECDSAPub(&key.PublicKey), nil
 }
 
-// todo: delete is tests pass
-//func (api *PublicWhisperAPI) GetPublicKey(id string) (string, error) {
-//	if api.whisper == nil {
-//		return "", whisperOffLineErr
-//	}
-//	key, err := api.whisper.GetPrivateKey(id)
-//	if err != nil {
-//		return "", err
-//	}
-//	return common.ToHex(crypto.FromECDSAPub(&key.PublicKey)), nil
-//}
-
 // GetPrivateKey returns the private key for identity id
 func (api *PublicWhisperAPI) GetPrivateKey(id string) (string, error) {
 	if api.whisper == nil {
@@ -209,20 +197,6 @@ func (api *PublicWhisperAPI) GetSymmetricKey(name string) (hexutil.Bytes, error)
 	return b, nil
 }
 
-// todo: delete if tests pass
-//func (api *PublicWhisperAPI) GetSymmetricKey(name string) (string, error) {
-//	if api.whisper == nil {
-//		return "", whisperOffLineErr
-//	}
-//
-//	b, err := api.whisper.GetSymKey(name)
-//	if err != nil {
-//		return "", err
-//	}
-//	//return fmt.Sprintf("%x", b), nil // todo: delete if tests pass
-//	return common.ToHex(b), nil
-//}
-
 // DeleteSymmetricKey deletes the key associated with the name string if it exists.
 func (api *PublicWhisperAPI) DeleteSymmetricKey(name string) (bool, error) {
 	if api.whisper == nil {
diff --git a/whisper/whisperv5/envelope.go b/whisper/whisperv5/envelope.go
index ef2c54a04d..e61918fcb5 100644
--- a/whisper/whisperv5/envelope.go
+++ b/whisper/whisperv5/envelope.go
@@ -120,7 +120,7 @@ func (e *Envelope) Seal(options *MessageParams) error {
 	}
 
 	if target > 0 && bestBit < target {
-		return fmt.Errorf("Failed to reach the PoW target, specified pow time (%d seconds) was insufficient", options.WorkTime)
+		return fmt.Errorf("failed to reach the PoW target, specified pow time (%d seconds) was insufficient", options.WorkTime)
 	}
 
 	return nil
diff --git a/whisper/whisperv5/message.go b/whisper/whisperv5/message.go
index 7b0a3be714..98443da131 100644
--- a/whisper/whisperv5/message.go
+++ b/whisper/whisperv5/message.go
@@ -168,7 +168,7 @@ func (msg *SentMessage) sign(key *ecdsa.PrivateKey) error {
 // encryptAsymmetric encrypts a message with a public key.
 func (msg *SentMessage) encryptAsymmetric(key *ecdsa.PublicKey) error {
 	if !ValidatePublicKey(key) {
-		return fmt.Errorf("Invalid public key provided for asymmetric encryption")
+		return fmt.Errorf("invalid public key provided for asymmetric encryption")
 	}
 	encrypted, err := ecies.Encrypt(crand.Reader, ecies.ImportECDSAPublic(key), msg.Raw, nil, nil)
 	if err == nil {
@@ -238,7 +238,7 @@ func (msg *SentMessage) Wrap(options *MessageParams) (envelope *Envelope, err er
 	} else if options.KeySym != nil {
 		salt, nonce, err = msg.encryptSymmetric(options.KeySym)
 	} else {
-		err = errors.New("Unable to encrypt the message: neither Dst nor Key")
+		err = errors.New("unable to encrypt the message: neither symmetric nor assymmmetric key provided")
 	}
 
 	if err != nil {
@@ -270,7 +270,7 @@ func (msg *ReceivedMessage) decryptSymmetric(key []byte, salt []byte, nonce []by
 		return err
 	}
 	if len(nonce) != aesgcm.NonceSize() {
-		info := fmt.Sprintf("Wrong AES nonce size - want: %d, got: %d", len(nonce), aesgcm.NonceSize())
+		info := fmt.Sprintf("wrong AES nonce size - want: %d, got: %d", len(nonce), aesgcm.NonceSize())
 		log.Error(info)
 		return errors.New(info)
 	}
@@ -342,7 +342,7 @@ func (msg *ReceivedMessage) SigToPubKey() *ecdsa.PublicKey {
 
 	pub, err := crypto.SigToPub(msg.hash(), msg.Signature)
 	if err != nil {
-		log.Error(fmt.Sprintf("Could not get public key from signature: %v", err))
+		log.Error(fmt.Sprintf("could not get public key from signature: %v", err))
 		return nil
 	}
 	return pub
diff --git a/whisper/whisperv5/peer_test.go b/whisper/whisperv5/peer_test.go
index a1a9a1ffa2..cd5153dfd5 100644
--- a/whisper/whisperv5/peer_test.go
+++ b/whisper/whisperv5/peer_test.go
@@ -120,9 +120,6 @@ func initialize(t *testing.T) {
 		topics = append(topics, sharedTopic)
 		f := Filter{KeySym: sharedKey}
 		f.Topics = [][]byte{topics[0][:]}
-		// todo: delete if pass
-		//f.Topics = make([][]byte, 1)
-		//f.Topics[0] = topics[0][:]
 		node.filerId, err = node.shh.Watch(&f)
 		if err != nil {
 			t.Fatalf("failed to install the filter: %s.", err)
diff --git a/whisper/whisperv5/whisper.go b/whisper/whisperv5/whisper.go
index a0f8bd97ba..95474550d0 100644
--- a/whisper/whisperv5/whisper.go
+++ b/whisper/whisperv5/whisper.go
@@ -132,7 +132,7 @@ func (w *Whisper) Version() uint {
 // SetMaxMessageLength sets the maximal message length allowed by this node
 func (w *Whisper) SetMaxMessageLength(val int) error {
 	if val <= 0 {
-		return fmt.Errorf("Invalid message length: %d", val)
+		return fmt.Errorf("invalid message length: %d", val)
 	}
 	w.maxMsgLength = val
 	return nil
@@ -141,7 +141,7 @@ func (w *Whisper) SetMaxMessageLength(val int) error {
 // SetMinimumPoW sets the minimal PoW required by this node
 func (w *Whisper) SetMinimumPoW(val float64) error {
 	if val <= 0.0 {
-		return fmt.Errorf("Invalid PoW: %f", val)
+		return fmt.Errorf("invalid PoW: %f", val)
 	}
 	w.minPoW = val
 	return nil
@@ -190,7 +190,6 @@ func (w *Whisper) SendP2PMessage(peerID []byte, envelope *Envelope) error {
 	if err != nil {
 		return err
 	}
-	//return p2p.Send(p.ws, p2pCode, envelope) // todo: delete if tests pass
 	return w.SendP2PDirect(p, envelope)
 }
 
@@ -210,19 +209,19 @@ func (w *Whisper) NewKeyPair() (string, error) {
 		return "", err
 	}
 	if !validatePrivateKey(key) {
-		return "", fmt.Errorf("Failed to generate valid key")
+		return "", fmt.Errorf("failed to generate valid key")
 	}
 
 	id, err := GenerateRandomID()
 	if err != nil {
-		return "", fmt.Errorf("Failed to generate ID: %s", err)
+		return "", fmt.Errorf("failed to generate ID: %s", err)
 	}
 
 	w.keyMu.Lock()
 	defer w.keyMu.Unlock()
 
 	if w.privateKeys[id] != nil {
-		return "", fmt.Errorf("Failed to generate unique ID")
+		return "", fmt.Errorf("failed to generate unique ID")
 	}
 	w.privateKeys[id] = key
 	return id, nil
@@ -254,7 +253,7 @@ func (w *Whisper) GetPrivateKey(id string) (*ecdsa.PrivateKey, error) {
 	defer w.keyMu.RUnlock()
 	key := w.privateKeys[id]
 	if key == nil {
-		return nil, fmt.Errorf("GetPrivateKey: invalid id")
+		return nil, fmt.Errorf("invalid id")
 	}
 	return key, nil
 }
@@ -282,14 +281,14 @@ func (w *Whisper) GenerateSymKey() (string, error) {
 
 	id, err := GenerateRandomID()
 	if err != nil {
-		return "", fmt.Errorf("Failed to generate ID: %s", err)
+		return "", fmt.Errorf("failed to generate ID: %s", err)
 	}
 
 	w.keyMu.Lock()
 	defer w.keyMu.Unlock()
 
 	if w.symKeys[id] != nil {
-		return "", fmt.Errorf("Failed to generate unique ID")
+		return "", fmt.Errorf("failed to generate unique ID")
 	}
 	w.symKeys[id] = derived
 	return id, nil
@@ -298,19 +297,19 @@ func (w *Whisper) GenerateSymKey() (string, error) {
 // AddSymKeyDirect stores the key, and returns its id.
 func (w *Whisper) AddSymKeyDirect(key []byte) (string, error) {
 	if len(key) != aesKeyLength {
-		return "", fmt.Errorf("Wrong key size: %d", len(key))
+		return "", fmt.Errorf("wrong key size: %d", len(key))
 	}
 
 	id, err := GenerateRandomID()
 	if err != nil {
-		return "", fmt.Errorf("Failed to generate ID: %s", err)
+		return "", fmt.Errorf("failed to generate ID: %s", err)
 	}
 
 	w.keyMu.Lock()
 	defer w.keyMu.Unlock()
 
 	if w.symKeys[id] != nil {
-		return "", fmt.Errorf("Failed to generate unique ID")
+		return "", fmt.Errorf("failed to generate unique ID")
 	}
 	w.symKeys[id] = key
 	return id, nil
@@ -320,10 +319,10 @@ func (w *Whisper) AddSymKeyDirect(key []byte) (string, error) {
 func (w *Whisper) AddSymKeyFromPassword(password string) (string, error) {
 	id, err := GenerateRandomID()
 	if err != nil {
-		return "", fmt.Errorf("Failed to generate ID: %s", err)
+		return "", fmt.Errorf("failed to generate ID: %s", err)
 	}
 	if w.HasSymKey(id) {
-		return "", fmt.Errorf("Failed to generate unique ID")
+		return "", fmt.Errorf("failed to generate unique ID")
 	}
 
 	derived, err := deriveKeyMaterial([]byte(password), EnvelopeVersion)
@@ -336,7 +335,7 @@ func (w *Whisper) AddSymKeyFromPassword(password string) (string, error) {
 
 	// double check is necessary, because deriveKeyMaterial() is very slow
 	if w.symKeys[id] != nil {
-		return "", fmt.Errorf("Severe error: failed to generate unique ID")
+		return "", fmt.Errorf("critical error: failed to generate unique ID")
 	}
 	w.symKeys[id] = derived
 	return id, nil
@@ -749,7 +748,7 @@ func (s *Statistics) reset() {
 func ValidateKeyID(id string) error {
 	const target = keyIdSize * 2
 	if len(id) != target {
-		return fmt.Errorf("Wrong size of key ID (expected %d bytes, got %d)", target, len(id))
+		return fmt.Errorf("wrong size of key ID (expected %d bytes, got %d)", target, len(id))
 	}
 	return nil
 }