diff --git a/src/main/wasm/memory-pow/Makefile b/src/main/wasm/memory-pow/Makefile
new file mode 100644
index 00000000..6d1f0a4c
--- /dev/null
+++ b/src/main/wasm/memory-pow/Makefile
@@ -0,0 +1,28 @@
+# Use GNU make
+
+# For FreeBSD 12. Probably comment these out for Linux, MacOS, etc.
+CLANG=/usr/local/llvm-devel/bin/clang
+LLVM_DWARFDUMP=/usr/local/llvm-devel/bin/llvm-dwarfdump
+WASM_SOURCEMAP_PY=/usr/local/lib/emscripten/tools/wasm-sourcemap.py
+
+
+.PHONY: all
+all: memory-pow memory-pow.wasm test.wasm
+
+clean:
+	rm -f memory-pow *.wasm*
+
+%.wasm.full: %.c Makefile
+	${CLANG} -g -Os --target=wasm32 --no-standard-libraries -Wl,--export-all -Wl,--no-entry -Wl,--import-memory -o $@ $<
+
+%.wasm.dwarf: %.wasm.full
+	${LLVM_DWARFDUMP} $< > $@
+
+%.wasm: %.wasm.full %.wasm.dwarf
+	${WASM_SOURCEMAP_PY} -w $@ --sources --prefix $(CURDIR) --source-map-url http://localhost:8080/$(@:.wasm=.wasm.map) --output $(@:.wasm=.wasm.map) --dwarfdump-output $(@:.wasm=.wasm.dwarf) $<
+
+memory-pow: memory-pow-main.c memory-pow.c
+	cc -Os -g -L/usr/local/lib -o memory-pow memory-pow-main.c -lssl -lcrypto
+
+emrun:
+	emrun  --no_browser --port 8080 .
diff --git a/src/main/wasm/memory-pow/memory-pow-main.c b/src/main/wasm/memory-pow/memory-pow-main.c
new file mode 100644
index 00000000..3b5043bc
--- /dev/null
+++ b/src/main/wasm/memory-pow/memory-pow-main.c
@@ -0,0 +1,59 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <openssl/evp.h>
+
+#define NO_STDINT_TYPEDEFS
+#include "memory-pow.c"
+
+	unsigned int toInt(char c) {
+		if (c >= '0' && c <= '9') return      c - '0';
+		if (c >= 'A' && c <= 'F') return 10 + c - 'A';
+		if (c >= 'a' && c <= 'f') return 10 + c - 'a';
+		return -1;
+	}
+
+	void hexToRaw(char *hex, uint8_t *data, int dataLength) {
+		for (int i = 0; i < dataLength; ++i) {
+			data[i] = 16 * toInt(hex[i * 2]) + toInt(hex[i * 2 + 1]);
+		}
+	}
+
+	void digest(uint8_t *message, int messageLength, uint8_t *hash) {
+		EVP_MD_CTX *mdctx = EVP_MD_CTX_new();
+		const EVP_MD *md = EVP_sha256();
+
+		EVP_DigestInit_ex(mdctx, md, NULL);
+		EVP_DigestUpdate(mdctx, message, messageLength);
+		EVP_DigestFinal_ex(mdctx, hash, NULL);
+	}
+
+	int main(int argc, char *argv[], char *env[]) {
+		if (argc < 2) {
+			fprintf(stderr, "usage: %s hex [difficulty]\n", argv[0]);
+			return 2;
+		}
+
+		int dataLength = strlen(argv[1]) / 2;
+		uint8_t data[dataLength];
+		hexToRaw(argv[1], data, dataLength);
+
+		int difficulty = 12;
+		if (argc > 2)
+			sscanf(argv[2], "%d", &difficulty);
+
+		printf("Using difficulty: %d\n", difficulty);
+
+		// Hash data with SHA256
+		uint8_t hash[32];
+		digest(data, dataLength, hash);
+
+		size_t workBufferLength = 8 * 1024 * 1024;
+		uint64_t *workBuffer = (uint64_t *) malloc(workBufferLength);
+
+		uint32_t nonce = compute2(hash, workBuffer, workBufferLength, difficulty);
+
+		printf("nonce: %d\n", nonce);
+	}
diff --git a/src/main/wasm/memory-pow/memory-pow.c b/src/main/wasm/memory-pow/memory-pow.c
new file mode 100644
index 00000000..e8ac45c2
--- /dev/null
+++ b/src/main/wasm/memory-pow/memory-pow.c
@@ -0,0 +1,88 @@
+#ifndef NO_STDINT_TYPEDEFS
+	typedef unsigned char uint8_t;
+	typedef unsigned int uint32_t;
+	typedef unsigned long long uint64_t;
+#endif
+
+#define WORKBUFFER_LENGTH (longBufferLength / 8)
+#define INTEGER_MAX_VALUE 0x7fffffffULL
+
+uint64_t xoshiro256p(uint64_t state[]) {
+	uint64_t result = state[0] + state[3];
+	uint64_t temp = state[1] << 17;
+
+	state[2] ^= state[0];
+	state[3] ^= state[1];
+	state[1] ^= state[2];
+	state[0] ^= state[3];
+
+	state[2] ^= temp;
+	state[3] = (state[3] << 45) | (state[3] >> (64 - 45)); // rol64(s[3], 45);
+
+	return result;
+}
+
+int numberOfLeadingZeros32(uint32_t i) {
+	if (i <= 0)
+		return i == 0 ? 32 : 0;
+	int n = 31;
+	if (i >= 1 << 16) { n -= 16; i >>= 16; }
+	if (i >= 1 <<  8) { n -=  8; i >>=  8; }
+	if (i >= 1 <<  4) { n -=  4; i >>=  4; }
+	if (i >= 1 <<  2) { n -=  2; i >>=  2; }
+	return n - (i >> 1);
+}
+
+int numberOfLeadingZeros64(uint64_t i) {
+	uint32_t x = (uint32_t) (i >> 32);
+	return x == 0
+			? 32 + numberOfLeadingZeros32((uint32_t) i)
+			: numberOfLeadingZeros32(x);
+}
+
+uint32_t compute2(uint8_t *hash, uint64_t *workBuffer, uint32_t workBufferLength, int difficulty) {
+	uint64_t longHash[4];
+	for (int l = 0; l < 4; ++l) {
+		longHash[l] = 0;
+
+		for (int b = 0; b < 8; ++b) {
+			longHash[l] = longHash[l] << 8 | hash[l * 8 + b];
+		}
+	}
+
+	uint32_t longBufferLength = workBufferLength / 8;
+
+	uint64_t state[4] = { 0, 0, 0, 0 };
+
+	uint64_t seed = 8682522807148012ULL;
+	uint64_t seedMultiplier = 1181783497276652981ULL;
+
+	// For each nonce...
+	uint32_t nonce = -1;
+	uint64_t result = 0;
+	do {
+		++nonce;
+
+		seed *= seedMultiplier; // per nonce
+
+		state[0] = longHash[0] ^ seed;
+		state[1] = longHash[1] ^ seed;
+		state[2] = longHash[2] ^ seed;
+		state[3] = longHash[3] ^ seed;
+
+		// Fill work buffer with random
+		for (uint32_t i = 0; i < WORKBUFFER_LENGTH; ++i)
+			workBuffer[i] = xoshiro256p(state);
+
+		// Random bounce through whole buffer
+		result = workBuffer[0];
+		for (uint32_t i = 0; i < 1024; ++i) {
+			uint32_t index = (uint32_t) (xoshiro256p(state) & INTEGER_MAX_VALUE) % WORKBUFFER_LENGTH;
+			result ^= workBuffer[index];
+		}
+
+		// Return if final value > difficulty
+	} while (numberOfLeadingZeros64(result) < difficulty);
+
+	return nonce;
+}
diff --git a/src/main/wasm/memory-pow/memory-pow.html b/src/main/wasm/memory-pow/memory-pow.html
new file mode 100644
index 00000000..9dc43301
--- /dev/null
+++ b/src/main/wasm/memory-pow/memory-pow.html
@@ -0,0 +1,41 @@
+<!doctype html>
+<html>
+	<head>
+		<script>
+			var memory = new WebAssembly.Memory({ initial: 256, maximum: 256 });
+			var heap = new Uint8Array(memory.buffer);
+			var brk = 512 * 1024; // stack top
+
+			var sbrk = function(size) {
+				var old = brk;
+				brk += size;
+
+				if (brk > heap.length)
+					throw new Error("heap exhausted");
+
+				return old;
+			};
+
+			var importObject = {
+				env: { 
+					memory: memory
+				},
+			};
+
+			WebAssembly.instantiateStreaming(fetch('memory-pow.wasm'), importObject)
+			.then(obj => {
+				window.instance = obj.instance;
+				window._compute2 = obj.instance.exports.compute2;
+			});
+
+			var hashPtr = sbrk(32);
+			var hashAry = new Uint8Array(memory.buffer, hashPtr, 32);
+			hashAry.set([250, 34, 223, 225, 218, 144, 19, 179, 193, 20, 80, 64, 172, 174, 144, 137, 224, 192, 139, 193, 193, 160, 113, 150, 20, 244, 183, 58, 221, 111, 110, 245]);
+
+			var workBufferLength = 8 * 1024 * 1024;
+			var workBufferPtr = sbrk(workBufferLength);
+		</script>
+	</head>
+	<body>
+	</body>
+</html>
\ No newline at end of file
diff --git a/src/main/wasm/memory-pow/test.c b/src/main/wasm/memory-pow/test.c
new file mode 100644
index 00000000..5b3d7b97
--- /dev/null
+++ b/src/main/wasm/memory-pow/test.c
@@ -0,0 +1,67 @@
+typedef unsigned char uint8_t;
+typedef unsigned int uint32_t;
+typedef unsigned long long uint64_t;
+
+uint32_t test() {
+	return 4013;
+}
+
+uint32_t test2(uint8_t values[], int count) {
+	uint32_t sum = 0;
+
+	for (int i = 0; i < count; ++i)
+		sum += values[i];
+
+	return sum;
+}
+
+void test3(uint8_t hash[], uint64_t longHash[]) {
+	for (int l = 0; l < 4; ++l) {
+		longHash[l] = 0;
+
+		for (int b = 0; b < 8; ++b)
+			longHash[l] = longHash[l] << 8 | hash[l * 8 + b];
+	}
+}
+
+void test4(uint64_t *result) {
+	uint64_t seed = 8682522807148012ULL;
+	uint64_t seedMultiplier = 1181783497276652981ULL;
+
+	*result = seed * seedMultiplier;
+}
+
+void test5(uint64_t longHash[], uint64_t state[]) {
+	uint64_t seed = 8682522807148012ULL;
+	uint64_t seedMultiplier = 1181783497276652981ULL;
+
+	seed *= seedMultiplier; // per nonce
+
+	state[0] = longHash[0] ^ seed;
+	state[1] = longHash[1] ^ seed;
+	state[2] = longHash[2] ^ seed;
+	state[3] = longHash[3] ^ seed;
+}
+
+uint32_t shr(uint32_t in, int shift) {
+	return in >> shift;
+}
+
+void xoshiro256p(uint64_t state[], uint64_t *result) {
+	*result = state[0] + state[3];
+	uint64_t temp = state[1] << 17;
+
+	state[2] ^= state[0];
+	state[3] ^= state[1];
+	state[1] ^= state[2];
+	state[0] ^= state[3];
+
+	state[2] ^= temp;
+	state[3] = (state[3] << 45) | (state[3] >> (64 - 45)); // rol64(s[3], 45);
+}
+
+void fillWorkBuffer(uint64_t workBuffer[], int workBufferLength, uint64_t state[]) {
+	// Fill work buffer with random
+	for (uint32_t i = 0; i < workBufferLength; ++i)
+		xoshiro256p(state, &workBuffer[i]);
+}
diff --git a/src/main/wasm/memory-pow/test.html b/src/main/wasm/memory-pow/test.html
new file mode 100644
index 00000000..383f0c54
--- /dev/null
+++ b/src/main/wasm/memory-pow/test.html
@@ -0,0 +1,53 @@
+<!doctype html>
+<html>
+	<head>
+		<script>
+			var memory = new WebAssembly.Memory({ initial: 256, maximum: 256 });
+			var heap = new Uint8Array(memory.buffer);
+			var brk = 512 * 1024; // stack top
+
+			var sbrk = function(size) {
+				var old = brk;
+				brk += size;
+
+				if (brk > heap.length)
+					throw new Error("heap exhausted");
+
+				return old;
+			};
+
+			var importObject = {
+				env: { 
+					memory: memory,
+				},
+			};
+
+			WebAssembly.instantiateStreaming(fetch('test.wasm'), importObject)
+			.then(obj => {
+				window.instance = obj.instance;
+				for (f in obj.instance.exports)
+					if (obj.instance.exports[f] instanceof Function && f.charAt(0) != '_')
+						window["_" + f] = obj.instance.exports[f];
+			});
+
+			var hashPtr = sbrk(32);
+			var hashAry = new Uint8Array(memory.buffer, hashPtr, 32);
+			hashAry.set([250, 34, 223, 225, 218, 144, 19, 179, 193, 20, 80, 64, 172, 174, 144, 137, 224, 192, 139, 193, 193, 160, 113, 150, 20, 244, 183, 58, 221, 111, 110, 245]);
+
+			var longHashPtr = sbrk(4 * 8);
+			var longHashAry = new BigUint64Array(memory.buffer, longHashPtr, 4);
+
+			var statePtr = sbrk(4 * 8);
+			var stateAry = new BigUint64Array(memory.buffer, statePtr, 4);
+
+			var resultPtr = sbrk(8);
+			var resultAry = new BigUint64Array(memory.buffer, resultPtr, 1);
+
+			var workBufferLength = 8 * 1024 * 1024;
+			var workBufferPtr = sbrk(workBufferLength);
+			var workBufferAry = new BigUint64Array(memory.buffer, workBufferPtr, workBufferLength / 8);
+		</script>
+	</head>
+	<body>
+	</body>
+</html>
\ No newline at end of file
diff --git a/src/test/java/org/qortal/test/MemoryPoWTests.java b/src/test/java/org/qortal/test/MemoryPoWTests.java
index 6232ae06..1e7f8946 100644
--- a/src/test/java/org/qortal/test/MemoryPoWTests.java
+++ b/src/test/java/org/qortal/test/MemoryPoWTests.java
@@ -67,4 +67,15 @@ public class MemoryPoWTests {
 		System.out.println(String.format("Max nonce: %d", maxNonce));
 	}
 
+	@Test
+	public void testKnownCompute2() {
+		byte[] data = new byte[] { (byte) 0xaa, (byte) 0xbb, (byte) 0xcc };
+
+		int expectedNonce = 4013;
+		int nonce = MemoryPoW.compute2(data, 8 * 1024 * 1024, 12);
+
+		System.out.println(String.format("Nonce: %d", nonce));
+		assertEquals(expectedNonce, nonce);
+	}
+
 }