diff --git a/convex-core/src/main/cvx/convex/core/metadata.cvx b/convex-core/src/main/cvx/convex/core/metadata.cvx
index ca4ebad1c..b8463ab87 100644
--- a/convex-core/src/main/cvx/convex/core/metadata.cvx
+++ b/convex-core/src/main/cvx/convex/core/metadata.cvx
@@ -604,6 +604,18 @@
                       {:code "(hash (encoding :foo))"}]
         :signature   [{:params [value]
                        :return Blob}]}}
+ 
+ keccak256
+ {:doc {:description "Calculates the 32-byte Keccak-256 cryptographic hash of a `blob` or an `address` (which is a specialized type of `blob`). Returns a 32-byte `blob`."
+        :examples    [{:code "(keccak256 0x1234)"}]
+        :signature   [{:params [value]
+                       :return Blob}]}}
+ 
+ sha256
+ {:doc {:description "Calculates the 32-byte SHA-256 cryptographic hash of a `blob` or an `address` (which is a specialized type of `blob`). Returns a 32-byte `blob`."
+        :examples    [{:code "(sha256 0x1234)"}]
+        :signature   [{:params [value]
+                       :return Blob}]}}
 
  hash-map
  {:doc {:description "Constructs a map with the given keys and values. If a key is repeated, the last value will overwrite previous ones."
diff --git a/convex-core/src/main/java/convex/core/crypto/Hashing.java b/convex-core/src/main/java/convex/core/crypto/Hashing.java
index 05abd52c1..879a97e09 100644
--- a/convex-core/src/main/java/convex/core/crypto/Hashing.java
+++ b/convex-core/src/main/java/convex/core/crypto/Hashing.java
@@ -79,16 +79,28 @@ public static MessageDigest getSHA256Digest() {
 	}
 
 	/**
-	 * Computes the SHA3-256 hash of byte data
+	 * Computes the SHA-256 hash of byte data
 	 * 
 	 * @param data Byte array to hash
-	 * @return SHA3-256 Hash value
+	 * @return Hash value
 	 */
 	public static Hash sha256(byte[] data) {
 		MessageDigest md = getSHA256Digest();
 		byte[] hash = md.digest(data);
 		return Hash.wrap(hash);
 	}
+	
+	/**
+	 * Computes the KECCAK-256 hash of byte data
+	 * 
+	 * @param data Byte array to hash
+	 * @return Hash value
+	 */
+	public static Hash keccak256(byte[] data) {
+		MessageDigest md = getKeccak256Digest();
+		byte[] hash = md.digest(data);
+		return Hash.wrap(hash);
+	}
 
 	/**
 	 * Computes the SHA-256 hash of a string
diff --git a/convex-core/src/main/java/convex/core/lang/Core.java b/convex-core/src/main/java/convex/core/lang/Core.java
index 9730992af..51513964f 100644
--- a/convex-core/src/main/java/convex/core/lang/Core.java
+++ b/convex-core/src/main/java/convex/core/lang/Core.java
@@ -10,6 +10,7 @@
 import convex.core.Constants;
 import convex.core.ErrorCodes;
 import convex.core.State;
+import convex.core.crypto.Hashing;
 import convex.core.data.ABlob;
 import convex.core.data.ACell;
 import convex.core.data.ACountable;
@@ -2061,21 +2062,51 @@ public  Context invoke(Context context, ACell[] args) {
 	});
 
 	public static final CoreFn<Hash> HASH = reg(new CoreFn<>(Symbols.HASH) {
-		
 		@Override
 		public  Context invoke(Context context, ACell[] args) {
 			if (args.length != 1) return context.withArityError(exactArityMessage(1, args.length));
 
 			ABlob blob=RT.ensureBlob(args[0]);
 			if (blob==null) return context.withCastError(0,args, Types.BLOB);
+			long juice=Juice.HASH+blob.count()*Juice.HASH_PER_BYTE;
+			if (!context.checkJuice(juice)) return context.withJuiceError();
 
 			Hash result = blob.getContentHash();
-			return context.withResult(Juice.HASH, result);
+			return context.withResult(juice, result);
 		}
 	});
+	
+	public static final CoreFn<Hash> KECCAK256 = reg(new CoreFn<>(Symbols.KECCAK256) {
+		@Override
+		public  Context invoke(Context context, ACell[] args) {
+			if (args.length != 1) return context.withArityError(exactArityMessage(1, args.length));
 
-	public static final CoreFn<CVMLong> COUNT = reg(new CoreFn<>(Symbols.COUNT) {
-		
+			ABlob blob=RT.ensureBlob(args[0]);
+			if (blob==null) return context.withCastError(0,args, Types.BLOB);
+			long juice=Juice.HASH+blob.count()*Juice.HASH_PER_BYTE;
+			if (!context.checkJuice(juice)) return context.withJuiceError();
+
+			Hash result = blob.computeHash(Hashing.getKeccak256Digest());
+			return context.withResult(juice, result);
+		}
+	});
+	
+	public static final CoreFn<Hash> SHA256 = reg(new CoreFn<>(Symbols.SHA256) {
+		@Override
+		public  Context invoke(Context context, ACell[] args) {
+			if (args.length != 1) return context.withArityError(exactArityMessage(1, args.length));
+
+			ABlob blob=RT.ensureBlob(args[0]);
+			if (blob==null) return context.withCastError(0,args, Types.BLOB);
+			long juice=Juice.HASH+blob.count()*Juice.HASH_PER_BYTE;
+			if (!context.checkJuice(juice)) return context.withJuiceError();
+
+			Hash result = blob.computeHash(Hashing.getSHA256Digest());
+			return context.withResult(juice, result);
+		}
+	});
+
+	public static final CoreFn<CVMLong> COUNT = reg(new CoreFn<>(Symbols.COUNT) {	
 		@Override
 		public  Context invoke(Context context, ACell[] args) {
 			if (args.length != 1) return context.withArityError(exactArityMessage(1, args.length));
@@ -2088,7 +2119,6 @@ public  Context invoke(Context context, ACell[] args) {
 	});
 
 	public static final CoreFn<ACell> EMPTY = reg(new CoreFn<>(Symbols.EMPTY) {
-		
 		@Override
 		public  Context invoke(Context context, ACell[] args) {
 			if (args.length != 1) return context.withArityError(exactArityMessage(1, args.length));
diff --git a/convex-core/src/main/java/convex/core/lang/Juice.java b/convex-core/src/main/java/convex/core/lang/Juice.java
index de7ad8340..d6e5a9155 100644
--- a/convex-core/src/main/java/convex/core/lang/Juice.java
+++ b/convex-core/src/main/java/convex/core/lang/Juice.java
@@ -152,11 +152,16 @@ public class Juice {
 	public static final long APPLY = 50;
 
 	/**
-	 * Juice for a cryptographic hash
+	 * Base juice for a cryptographic hash
 	 * 
 	 * Expensive.
 	 */
-	public static final long HASH = 10000;
+	public static final long HASH = 1000;
+	
+	/**
+	 * Juice per byte of a cryptographic hash
+	 */
+	public static final long HASH_PER_BYTE = 10;
 
 	/**
 	 * Juice for a very cheap operation. O(1), no new cell allocations or non-trivial lookups.
diff --git a/convex-core/src/main/java/convex/core/lang/Symbols.java b/convex-core/src/main/java/convex/core/lang/Symbols.java
index 4f16acdf7..95efb160d 100644
--- a/convex-core/src/main/java/convex/core/lang/Symbols.java
+++ b/convex-core/src/main/java/convex/core/lang/Symbols.java
@@ -64,7 +64,10 @@ public class Symbols {
 	public static final Symbol CATCH = intern("catch");
 
 	public static final Symbol APPLY = intern("apply");
+	
 	public static final Symbol HASH = intern("hash");
+	public static final Symbol KECCAK256 = intern("keccak256");
+	public static final Symbol SHA256 = intern("sha256");
 
 	public static final Symbol QUOTE = intern("quote");
 	public static final Symbol QUASIQUOTE = intern("quasiquote");
@@ -325,8 +328,6 @@ public class Symbols {
 	public static final Symbol MEMORY_VALUE = intern("memory-value");
 	public static final Symbol PROTOCOL = intern("protocol");
 	
-
-	
 	public static Symbol intern(String s) {
 		AString name=Strings.create(s);
 		Symbol sym=Symbol.create(name);
diff --git a/convex-core/src/main/java/convex/core/util/Utils.java b/convex-core/src/main/java/convex/core/util/Utils.java
index 2aad177b2..13374bd9f 100644
--- a/convex-core/src/main/java/convex/core/util/Utils.java
+++ b/convex-core/src/main/java/convex/core/util/Utils.java
@@ -722,7 +722,7 @@ public static int toInt(Object v) {
 	public static String readResourceAsString(String path) throws IOException {
 		ClassLoader classLoader = ClassLoader.getSystemClassLoader();
 		try (InputStream inputStream = classLoader.getResourceAsStream(path)) {
-			if (inputStream == null) throw new IOException("Resource not found: " + path);
+			if (inputStream == null) throw new IOException("Resource not found: " + path + " with classloader "+classLoader);
 			try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
 				return reader.lines().collect(Collectors.joining(System.lineSeparator()));
 			}
diff --git a/convex-core/src/test/java/convex/core/lang/CoreTest.java b/convex-core/src/test/java/convex/core/lang/CoreTest.java
index 6e5b4aeb7..c3c6d0c9c 100644
--- a/convex-core/src/test/java/convex/core/lang/CoreTest.java
+++ b/convex-core/src/test/java/convex/core/lang/CoreTest.java
@@ -3391,6 +3391,7 @@ public void testExp() {
 	@Test
 	public void testHash() {
 		assertEquals(Hash.fromHex("a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a"),eval("(hash 0x)"));
+		assertEquals(Hash.fromHex("352B82608DAD6C7AC3DD665BC2666E5D97803CB13F23A1109E2105E93F42C448"),eval("(hash 0xDEADBEEF)"));
 
 		assertEquals(Hash.NULL_HASH, eval("(hash (encoding nil))"));
 		assertEquals(Hash.TRUE_HASH, eval("(hash (encoding true))"));
@@ -3406,6 +3407,38 @@ public void testHash() {
 		assertArityError(step("(hash)"));
 		assertArityError(step("(hash nil nil)"));
 	}
+	
+	@Test
+	public void testKeccak() {
+		assertEquals(Hash.fromHex("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470"),eval("(keccak256 0x)"));
+
+		assertTrue(evalB("(= (keccak256 0x1234) (keccak256 0x1234))"));
+		assertTrue(evalB("(blob? (keccak256 0x00))")); // Should be a Blob
+		
+		assertCastError(step("(keccak256 nil)"));
+		assertCastError(step("(keccak256 :foo)"));
+		assertCastError(step("(keccak256 #44)")); // specialised blobs don't implicitly cast to Blob
+		
+		assertArityError(step("(keccak256)"));
+		assertArityError(step("(keccak256 nil nil)"));
+	}
+	
+	@Test
+	public void testSHA256() {
+		assertEquals(Hash.fromHex("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"),eval("(sha256 0x)"));
+		assertEquals(Hash.fromHex("5F78C33274E43FA9DE5659265C1D917E25C03722DCB0B8D27DB8D5FEAA813953"),eval("(sha256 0xdeadbeef)"));
+
+		assertTrue(evalB("(= (sha256 0x1234) (sha256 0x1234))"));
+		assertTrue(evalB("(blob? (sha256 0x00))")); // Should be a Blob
+		
+		assertCastError(step("(sha256 nil)"));
+		assertCastError(step("(sha256 :foo)"));
+		assertCastError(step("(sha256 #44)")); // specialised blobs don't implicitly cast to Blob
+		
+		assertArityError(step("(sha256)"));
+		assertArityError(step("(sha256 nil nil)"));
+	}
+
 
 	@Test
 	public void testCount() {
diff --git a/convex-core/src/test/java/convex/lib/SimpleNFTTest.java b/convex-core/src/test/java/convex/lib/SimpleNFTTest.java
index 433669106..925b9da14 100644
--- a/convex-core/src/test/java/convex/lib/SimpleNFTTest.java
+++ b/convex-core/src/test/java/convex/lib/SimpleNFTTest.java
@@ -42,7 +42,6 @@ private static State createState() {
 		assertNotError(c);
 	}
 	
-	
 	@SuppressWarnings("unchecked")
 	@Test public void testAssetAPI() {
 		Context ctx=context();