diff --git a/common/src/main/java/com/msd/gin/halyard/common/ByteArray.java b/common/src/main/java/com/msd/gin/halyard/common/ByteArray.java
index eceff9ade..c717b14ff 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/ByteArray.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/ByteArray.java
@@ -27,6 +27,12 @@ public ByteBuffer writeTo(ByteBuffer bb) {
 		return bb.put(arr);
 	}
 
+	@Override
+	public ByteBuffer asReadOnlyBuffer() {
+		return ByteBuffer.wrap(arr).asReadOnlyBuffer();
+	}
+
+	@Override
 	public byte[] copyBytes() {
 		byte[] copy = new byte[arr.length];
 		System.arraycopy(arr, 0, copy, 0, arr.length);
diff --git a/common/src/main/java/com/msd/gin/halyard/common/ByteSequence.java b/common/src/main/java/com/msd/gin/halyard/common/ByteSequence.java
index 347191394..876dda8d1 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/ByteSequence.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/ByteSequence.java
@@ -12,6 +12,12 @@ public abstract class ByteSequence {
 	public abstract ByteBuffer writeTo(ByteBuffer bb);
 	public abstract int size();
 
+	public ByteBuffer asReadOnlyBuffer() {
+		ByteBuffer bb = ByteBuffer.allocate(size());
+		writeTo(bb);
+		return bb.asReadOnlyBuffer();
+	}
+
 	public byte[] copyBytes() {
 		byte[] copy = new byte[size()];
 		writeTo(ByteBuffer.wrap(copy));
diff --git a/common/src/main/java/com/msd/gin/halyard/common/EmptyBytes.java b/common/src/main/java/com/msd/gin/halyard/common/EmptyBytes.java
index d14694161..8ce238368 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/EmptyBytes.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/EmptyBytes.java
@@ -3,11 +3,18 @@
 import java.nio.ByteBuffer;
 
 final class EmptyBytes extends ByteSequence {
+	private static final byte[] EMPTY_BYTES = new byte[0];
+
 	@Override
 	public ByteBuffer writeTo(ByteBuffer bb) {
 		return bb;
 	}
 
+	@Override
+	public byte[] copyBytes() {
+		return EMPTY_BYTES;
+	}
+
 	@Override
 	public int size() {
 		return 0;
diff --git a/common/src/main/java/com/msd/gin/halyard/common/Hashes.java b/common/src/main/java/com/msd/gin/halyard/common/Hashes.java
index 483586fb9..5b2b6f022 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/Hashes.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/Hashes.java
@@ -2,6 +2,7 @@
 
 import com.google.common.hash.Hashing;
 
+import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -75,7 +76,7 @@ public static byte[] toBytes(String s) {
 	}
 
 
-	public static abstract class HashFunction implements Function<byte[],byte[]> {
+	public static abstract class HashFunction implements Function<ByteBuffer,byte[]> {
 		private final String name;
 		private final int size;
 
@@ -97,12 +98,12 @@ public final int size() {
 		}
 
 		@Override
-		public final byte[] apply(byte[] bb) {
+		public final byte[] apply(ByteBuffer bb) {
 			byte[] hash = calculateHash(bb);
 			return (size != hash.length) ? Arrays.copyOf(hash, size) : hash;
 		}
 
-		protected abstract byte[] calculateHash(byte[] bb);
+		protected abstract byte[] calculateHash(ByteBuffer bb);
 	}
 
 	static final class MessageDigestHashFunction extends HashFunction {
@@ -114,7 +115,7 @@ static final class MessageDigestHashFunction extends HashFunction {
 		}
 
 		@Override
-		protected byte[] calculateHash(byte[] bb) {
+		protected byte[] calculateHash(ByteBuffer bb) {
 			try {
 				md.update(bb);
 				return md.digest();
@@ -133,7 +134,7 @@ static final class GuavaHashFunction extends HashFunction {
 		}
 
 		@Override
-		protected byte[] calculateHash(byte[] bb) {
+		protected byte[] calculateHash(ByteBuffer bb) {
 			return hf.hashBytes(bb).asBytes();
 		}
 	}
diff --git a/common/src/main/java/com/msd/gin/halyard/common/IdentifiableValue.java b/common/src/main/java/com/msd/gin/halyard/common/IdentifiableValue.java
index b434384aa..6ac285efb 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/IdentifiableValue.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/IdentifiableValue.java
@@ -137,18 +137,11 @@ protected final int getEncodingType() {
 	}
 
 	private IdSer createIdSer(ValueIdentifier id, boolean makeId, ByteArray ser, @Nonnull RDFFactory rdfFactory) {
-		byte[] serBytes;
 		if (ser == null) {
-			serBytes = rdfFactory.valueWriter.toBytes(this);
-			ser = new ByteArray(serBytes);
-		} else {
-			serBytes = null;
+			ser = new ByteArray(rdfFactory.valueWriter.toBytes(this));
 		}
 		if (id == null && makeId) {
-			if (serBytes == null) {
-				serBytes = ser.copyBytes();
-			}
-			id = rdfFactory.getId(serBytes);
+			id = rdfFactory.getId(ser);
 		}
 		return new IdSer(id, ser, rdfFactory);
 	}
diff --git a/common/src/main/java/com/msd/gin/halyard/common/RDFFactory.java b/common/src/main/java/com/msd/gin/halyard/common/RDFFactory.java
index a09e89d81..c1199642f 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/RDFFactory.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/RDFFactory.java
@@ -357,14 +357,14 @@ public ValueIdentifier id(Value v) {
 				IdentifiableValue idv = (IdentifiableValue) v;
 				id = idv.getId(this);
 			} else {
-				byte[] ser = valueWriter.toBytes(v);
+				ByteArray ser = new ByteArray(valueWriter.toBytes(v));
 				id = getId(ser);
 			}
 			return id;
 		}
 	}
 
-	ValueIdentifier getId(byte[] ser) {
+	ValueIdentifier getId(ByteSequence ser) {
 		return idFormat.id(ser, valueReader);
 	}
 
diff --git a/common/src/main/java/com/msd/gin/halyard/common/RDFValue.java b/common/src/main/java/com/msd/gin/halyard/common/RDFValue.java
index 2af3f0e94..337855bd7 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/RDFValue.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/RDFValue.java
@@ -52,7 +52,7 @@ protected final ValueIdentifier calculateId() {
 		if (val instanceof IdentifiableValue) {
 			return ((IdentifiableValue) val).getId(rdfFactory);
 		} else {
-			return rdfFactory.getId(getSerializedForm().copyBytes());
+			return rdfFactory.getId(getSerializedForm());
 		}
 	}
 
diff --git a/common/src/main/java/com/msd/gin/halyard/common/ValueIdentifier.java b/common/src/main/java/com/msd/gin/halyard/common/ValueIdentifier.java
index c36703c37..ddf81cd78 100644
--- a/common/src/main/java/com/msd/gin/halyard/common/ValueIdentifier.java
+++ b/common/src/main/java/com/msd/gin/halyard/common/ValueIdentifier.java
@@ -146,20 +146,21 @@ int getSaltSize() {
 		/**
 		 * Thread-safe.
 		 */
-		ValueIdentifier id(byte[] ser, ValueIO.Reader reader) {
+		ValueIdentifier id(ByteSequence ser, ValueIO.Reader reader) {
 			byte[] hash = new byte[size];
+			ByteBuffer serbb = ser.asReadOnlyBuffer();
 			if (hashFuncProvider != null) {
-				byte[] algoHash = hashFuncProvider.get().apply(ser);
+				byte[] algoHash = hashFuncProvider.get().apply(serbb);
 				System.arraycopy(algoHash, 0, hash, 0, algoHash.length);
 			}
-			ByteBuffer bb = ByteBuffer.wrap(ser);
-			ValueType type = reader.getValueType(bb);
+			serbb.rewind();
+			ValueType type = reader.getValueType(serbb);
 			CoreDatatype datatype;
 			Value val = null;
 			if (type == ValueType.LITERAL) {
-				datatype = reader.getCoreDatatype(bb);
+				datatype = reader.getCoreDatatype(serbb);
 				if (datatype == null) {
-					val = reader.readValue(bb, valueFactory);
+					val = reader.readValue(serbb, valueFactory);
 					datatype = ((Literal)val).getCoreDatatype();
 				}
 			} else {
@@ -168,7 +169,7 @@ ValueIdentifier id(byte[] ser, ValueIO.Reader reader) {
 
 			if (hasJavaHash) {
 				if (val == null) {
-					val = reader.readValue(bb, valueFactory);
+					val = reader.readValue(serbb, valueFactory);
 				}
 				int jhash = val.hashCode();
 				int i = size - 1;
@@ -328,6 +329,11 @@ public ByteBuffer writeTo(ByteBuffer bb) {
 		return bb.put(idBytes);
 	}
 
+	@Override
+	public ByteBuffer asReadOnlyBuffer() {
+		return ByteBuffer.wrap(idBytes).asReadOnlyBuffer();
+	}
+
 	ByteBuffer writeSliceTo(int offset, int len, ByteBuffer bb) {
 		return bb.put(idBytes, offset, len);
 	}
diff --git a/common/src/test/java/com/msd/gin/halyard/common/HashesTest.java b/common/src/test/java/com/msd/gin/halyard/common/HashesTest.java
index 705d60bcc..2f359a273 100644
--- a/common/src/test/java/com/msd/gin/halyard/common/HashesTest.java
+++ b/common/src/test/java/com/msd/gin/halyard/common/HashesTest.java
@@ -2,6 +2,8 @@
 
 import com.msd.gin.halyard.common.Hashes.HashFunction;
 
+import java.nio.ByteBuffer;
+
 import org.apache.hadoop.hbase.util.Bytes;
 import org.junit.jupiter.api.Test;
 
@@ -19,11 +21,11 @@ public void testHash16() {
 	@Test
 	public void testMurmur3() {
 		HashFunction hf = Hashes.getHash("Murmur3-128", 0);
-		byte[] h128 = hf.apply(Bytes.toBytes("foobar"));
+		byte[] h128 = hf.apply(ByteBuffer.wrap(Bytes.toBytes("foobar")));
 		assertEquals(128/Byte.SIZE, h128.length);
 
 		hf = Hashes.getHash("Murmur3-128", 8);
-		byte[] h64 = hf.apply(Bytes.toBytes("foobar"));
+		byte[] h64 = hf.apply(ByteBuffer.wrap(Bytes.toBytes("foobar")));
 		assertEquals(8, h64.length);
 	}
 
diff --git a/common/src/test/java/com/msd/gin/halyard/common/ValueIdentifierTest.java b/common/src/test/java/com/msd/gin/halyard/common/ValueIdentifierTest.java
index 58c100e16..e883f7be3 100644
--- a/common/src/test/java/com/msd/gin/halyard/common/ValueIdentifierTest.java
+++ b/common/src/test/java/com/msd/gin/halyard/common/ValueIdentifierTest.java
@@ -23,7 +23,7 @@ public void testHashCode_shortID() {
 		ValueFactory vf = SimpleValueFactory.getInstance();
 		ValueIdentifier.Format f = new ValueIdentifier.Format("Murmur3-128", 3, 1, TypeNibble.BIG_NIBBLE, false);
 		Literal l = vf.createLiteral("foobar");
-		ValueIdentifier id = f.id(ValueIO.getDefaultWriter().toBytes(l), ValueIO.getDefaultReader());
+		ValueIdentifier id = f.id(new ByteArray(ValueIO.getDefaultWriter().toBytes(l)), ValueIO.getDefaultReader());
 		assertThrows(IllegalArgumentException.class, () ->
 			id.valueHashCode(f)
 		);
@@ -34,7 +34,7 @@ public void testHashCode_longID() {
 		ValueFactory vf = SimpleValueFactory.getInstance();
 		ValueIdentifier.Format f = new ValueIdentifier.Format("Murmur3-128", 6, 1, TypeNibble.BIG_NIBBLE, true);
 		Literal l = vf.createLiteral("foobar");
-		ValueIdentifier id = f.id(ValueIO.getDefaultWriter().toBytes(l), ValueIO.getDefaultReader());
+		ValueIdentifier id = f.id(new ByteArray(ValueIO.getDefaultWriter().toBytes(l)), ValueIO.getDefaultReader());
 		assertEquals(l.hashCode(), id.valueHashCode(f));
 	}
 
@@ -44,7 +44,7 @@ public void testHashCode_nonCanonical() {
 		Literal expected = vf.createLiteral("2018-04-06Z", XSD.DATE);
 		ValueIdentifier.Format f = new ValueIdentifier.Format("Murmur3-128", 6, 1, TypeNibble.BIG_NIBBLE, true);
 		Literal l = vf.createLiteral("2018-04-06+00:00", XSD.DATE);
-		ValueIdentifier id = f.id(ValueIO.getDefaultWriter().toBytes(l), ValueIO.getDefaultReader());
+		ValueIdentifier id = f.id(new ByteArray(ValueIO.getDefaultWriter().toBytes(l)), ValueIO.getDefaultReader());
 		assertEquals(expected.hashCode(), id.valueHashCode(f));
 	}
 }
diff --git a/tools/src/main/java/com/msd/gin/halyard/tools/HalyardSummary.java b/tools/src/main/java/com/msd/gin/halyard/tools/HalyardSummary.java
index 6cc202943..4606501db 100644
--- a/tools/src/main/java/com/msd/gin/halyard/tools/HalyardSummary.java
+++ b/tools/src/main/java/com/msd/gin/halyard/tools/HalyardSummary.java
@@ -36,6 +36,7 @@
 import java.io.OutputStream;
 import java.math.BigInteger;
 import java.net.URI;
+import java.nio.ByteBuffer;
 import java.text.MessageFormat;
 import java.util.BitSet;
 import java.util.Collections;
@@ -453,7 +454,7 @@ public void reduce(ImmutableBytesWritable key, Iterable<LongWritable> values, Co
 	                            write(sliceRPred, RDFS.LABEL, SVF.createLiteral("slice rdfs:range with cardinality " + cardinality));
 	                            write(sliceRPred, CARDINALITY, SVF.createLiteral(BigInteger.valueOf(cardinality)));
 	                        }
-	                        IRI generatedRoot = SVF.createIRI(NAMESPACE, ByteUtils.encode(keyHash.apply(key.copyBytes())));
+	                        IRI generatedRoot = SVF.createIRI(NAMESPACE, ByteUtils.encode(keyHash.apply(ByteBuffer.wrap(key.copyBytes()))));
 	                        write(generatedRoot, slicePPred, firstKey);
 	                        write(generatedRoot, sliceDPred, SVF.createIRI(dis.readUTF()));
 	                        write(generatedRoot, sliceRPred, SVF.createIRI(dis.readUTF()));