diff --git a/common/bitutil/bitutil.go b/common/bitutil/bitutil.go
index 578da1cf49..99a8c2ee18 100644
--- a/common/bitutil/bitutil.go
+++ b/common/bitutil/bitutil.go
@@ -8,7 +8,6 @@
 package bitutil
 
 import (
-	"crypto/subtle"
 	"runtime"
 	"unsafe"
 )
@@ -16,19 +15,6 @@ import (
 const wordSize = int(unsafe.Sizeof(uintptr(0)))
 const supportsUnaligned = runtime.GOARCH == "386" || runtime.GOARCH == "amd64" || runtime.GOARCH == "ppc64" || runtime.GOARCH == "ppc64le" || runtime.GOARCH == "s390x"
 
-// XORBytes xors the bytes in a and b. The destination is assumed to have enough
-// space. Returns the number of bytes xor'd.
-//
-// If dst does not have length at least n,
-// XORBytes panics without writing anything to dst.
-//
-// dst and x or y may overlap exactly or not at all,
-// otherwise XORBytes may panic.
-//
-// Deprecated: use crypto/subtle.XORBytes
-func XORBytes(dst, a, b []byte) int {
-	return subtle.XORBytes(dst, a, b)
-}
 
 // ANDBytes ands the bytes in a and b. The destination is assumed to have enough
 // space. Returns the number of bytes and'd.
diff --git a/common/bitutil/bitutil_test.go b/common/bitutil/bitutil_test.go
index 1748029794..0cad12bda7 100644
--- a/common/bitutil/bitutil_test.go
+++ b/common/bitutil/bitutil_test.go
@@ -11,45 +11,6 @@ import (
 	"testing"
 )
 
-// Tests that bitwise XOR works for various alignments.
-func TestXOR(t *testing.T) {
-	for alignP := 0; alignP < 2; alignP++ {
-		for alignQ := 0; alignQ < 2; alignQ++ {
-			for alignD := 0; alignD < 2; alignD++ {
-				p := make([]byte, 1023)[alignP:]
-				q := make([]byte, 1023)[alignQ:]
-
-				for i := 0; i < len(p); i++ {
-					p[i] = byte(i)
-				}
-				for i := 0; i < len(q); i++ {
-					q[i] = byte(len(q) - i)
-				}
-				d1 := make([]byte, 1023+alignD)[alignD:]
-				d2 := make([]byte, 1023+alignD)[alignD:]
-
-				XORBytes(d1, p, q)
-				naiveXOR(d2, p, q)
-				if !bytes.Equal(d1, d2) {
-					t.Error("not equal", d1, d2)
-				}
-			}
-		}
-	}
-}
-
-// naiveXOR xors bytes one by one.
-func naiveXOR(dst, a, b []byte) int {
-	n := len(a)
-	if len(b) < n {
-		n = len(b)
-	}
-	for i := 0; i < n; i++ {
-		dst[i] = a[i] ^ b[i]
-	}
-	return n
-}
-
 // Tests that bitwise AND works for various alignments.
 func TestAND(t *testing.T) {
 	for alignP := 0; alignP < 2; alignP++ {
@@ -124,32 +85,6 @@ func TestTest(t *testing.T) {
 	}
 }
 
-// Benchmarks the potentially optimized XOR performance.
-func BenchmarkFastXOR1KB(b *testing.B) { benchmarkFastXOR(b, 1024) }
-func BenchmarkFastXOR2KB(b *testing.B) { benchmarkFastXOR(b, 2048) }
-func BenchmarkFastXOR4KB(b *testing.B) { benchmarkFastXOR(b, 4096) }
-
-func benchmarkFastXOR(b *testing.B, size int) {
-	p, q := make([]byte, size), make([]byte, size)
-
-	for i := 0; i < b.N; i++ {
-		XORBytes(p, p, q)
-	}
-}
-
-// Benchmarks the baseline XOR performance.
-func BenchmarkBaseXOR1KB(b *testing.B) { benchmarkBaseXOR(b, 1024) }
-func BenchmarkBaseXOR2KB(b *testing.B) { benchmarkBaseXOR(b, 2048) }
-func BenchmarkBaseXOR4KB(b *testing.B) { benchmarkBaseXOR(b, 4096) }
-
-func benchmarkBaseXOR(b *testing.B, size int) {
-	p, q := make([]byte, size), make([]byte, size)
-
-	for i := 0; i < b.N; i++ {
-		naiveXOR(p, p, q)
-	}
-}
-
 // Benchmarks the potentially optimized AND performance.
 func BenchmarkFastAND1KB(b *testing.B) { benchmarkFastAND(b, 1024) }
 func BenchmarkFastAND2KB(b *testing.B) { benchmarkFastAND(b, 2048) }