diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index 3b04c5e11..c51a2312b 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -22,8 +22,8 @@
 		},
 		{
 			"ImportPath": "github.com/ethereum/ethash",
-			"Comment": "v23.1-73-g67a0e12",
-			"Rev": "67a0e12a091de035ef083186247e84be2d863c62"
+			"Comment": "v23.1-81-g4039fd0",
+			"Rev": "4039fd095084679fb0bf3feae91d02506b5d67aa"
 		},
 		{
 			"ImportPath": "github.com/ethereum/serpent-go",
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
index 7291d58ba..c33bfccc4 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
@@ -34,13 +34,12 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/pow"
 )
 
 var minDifficulty = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
 
-var powlogger = logger.NewLogger("POW")
-
 type ParamsAndCache struct {
 	params *C.ethash_params
 	cache  *C.ethash_cache
@@ -92,10 +91,13 @@ func makeParamsAndCache(chainManager pow.ChainManager, blockNum uint64) (*Params
 		return nil, err
 	}
 
-	powlogger.Infoln("Making Cache")
+	glog.V(logger.Info).Infoln("Making cache")
 	start := time.Now()
-	C.ethash_mkcache(paramsAndCache.cache, paramsAndCache.params, (*C.uint8_t)(unsafe.Pointer(&seedHash[0])))
-	powlogger.Infoln("Took:", time.Since(start))
+	C.ethash_mkcache(paramsAndCache.cache, paramsAndCache.params, (*C.ethash_blockhash_t)(unsafe.Pointer(&seedHash[0])))
+
+	if glog.V(logger.Info) {
+		glog.Infoln("Took:", time.Since(start))
+	}
 
 	return paramsAndCache, nil
 }
@@ -131,9 +133,9 @@ func makeDAG(p *ParamsAndCache) *DAG {
 		for {
 			select {
 			case <-t.C:
-				powlogger.Infof("... still generating DAG (%v) ...\n", time.Since(tstart).Seconds())
+				glog.V(logger.Info).Infof("... still generating DAG (%v) ...\n", time.Since(tstart).Seconds())
 			case str := <-donech:
-				powlogger.Infof("... %s ...\n", str)
+				glog.V(logger.Info).Infof("... %s ...\n", str)
 				break done
 			}
 		}
@@ -193,30 +195,30 @@ func (pow *Ethash) UpdateDAG() {
 		pow.paramsAndCache = paramsAndCache
 		path := path.Join("/", "tmp", "dag")
 		pow.dag = nil
-		powlogger.Infoln("Retrieving DAG")
+		glog.V(logger.Info).Infoln("Retrieving DAG")
 		start := time.Now()
 
 		file, err := os.Open(path)
 		if err != nil {
-			powlogger.Infof("No DAG found. Generating new DAG in '%s' (this takes a while)...\n", path)
+			glog.V(logger.Info).Infof("No DAG found. Generating new DAG in '%s' (this takes a while)...\n", path)
 			pow.dag = makeDAG(paramsAndCache)
 			file = pow.writeDagToDisk(pow.dag, thisEpoch)
 			pow.dag.file = true
 		} else {
 			data, err := ioutil.ReadAll(file)
 			if err != nil {
-				powlogger.Infof("DAG load err: %v\n", err)
+				glog.V(logger.Info).Infof("DAG load err: %v\n", err)
 			}
 
 			if len(data) < 8 {
-				powlogger.Infof("DAG in '%s' is less than 8 bytes, it must be corrupted. Generating new DAG (this takes a while)...\n", path)
+				glog.V(logger.Info).Infof("DAG in '%s' is less than 8 bytes, it must be corrupted. Generating new DAG (this takes a while)...\n", path)
 				pow.dag = makeDAG(paramsAndCache)
 				file = pow.writeDagToDisk(pow.dag, thisEpoch)
 				pow.dag.file = true
 			} else {
 				dataEpoch := binary.BigEndian.Uint64(data[0:8])
 				if dataEpoch < thisEpoch {
-					powlogger.Infof("DAG in '%s' is stale. Generating new DAG (this takes a while)...\n", path)
+					glog.V(logger.Info).Infof("DAG in '%s' is stale. Generating new DAG (this takes a while)...\n", path)
 					pow.dag = makeDAG(paramsAndCache)
 					file = pow.writeDagToDisk(pow.dag, thisEpoch)
 					pow.dag.file = true
@@ -224,7 +226,7 @@ func (pow *Ethash) UpdateDAG() {
 					// FIXME
 					panic(fmt.Errorf("Saved DAG in '%s' reports to be from future epoch %v (current epoch is %v)\n", path, dataEpoch, thisEpoch))
 				} else if len(data) != (int(paramsAndCache.params.full_size) + 8) {
-					powlogger.Infof("DAG in '%s' is corrupted. Generating new DAG (this takes a while)...\n", path)
+					glog.V(logger.Info).Infof("DAG in '%s' is corrupted. Generating new DAG (this takes a while)...\n", path)
 					pow.dag = makeDAG(paramsAndCache)
 					file = pow.writeDagToDisk(pow.dag, thisEpoch)
 					pow.dag.file = true
@@ -238,7 +240,7 @@ func (pow *Ethash) UpdateDAG() {
 				}
 			}
 		}
-		powlogger.Infoln("Took:", time.Since(start))
+		glog.V(logger.Info).Infoln("Took:", time.Since(start))
 
 		file.Close()
 	}
@@ -319,7 +321,7 @@ func (pow *Ethash) Search(block pow.Block, stop <-chan struct{}) (uint64, []byte
 	start := time.Now().UnixNano()
 
 	nonce := uint64(r.Int63())
-	cMiningHash := (*C.uint8_t)(unsafe.Pointer(&miningHash[0]))
+	cMiningHash := (*C.ethash_blockhash_t)(unsafe.Pointer(&miningHash[0]))
 	target := new(big.Int).Div(minDifficulty, diff)
 
 	var ret C.ethash_return_value
@@ -336,11 +338,11 @@ func (pow *Ethash) Search(block pow.Block, stop <-chan struct{}) (uint64, []byte
 			pow.HashRate = int64(hashes)
 
 			C.ethash_full(&ret, pow.dag.dag, pow.dag.paramsAndCache.params, cMiningHash, C.uint64_t(nonce))
-			result := common.Bytes2Big(C.GoBytes(unsafe.Pointer(&ret.result[0]), C.int(32)))
+			result := common.Bytes2Big(C.GoBytes(unsafe.Pointer(&ret.result), C.int(32)))
 
 			// TODO: disagrees with the spec https://github.com/ethereum/wiki/wiki/Ethash#mining
 			if result.Cmp(target) <= 0 {
-				mixDigest := C.GoBytes(unsafe.Pointer(&ret.mix_hash[0]), C.int(32))
+				mixDigest := C.GoBytes(unsafe.Pointer(&ret.mix_hash), C.int(32))
 				seedHash, err := GetSeedHash(block.NumberU64()) // This seedhash is useless
 				if err != nil {
 					panic(err)
@@ -366,14 +368,14 @@ func (pow *Ethash) Verify(block pow.Block) bool {
 func (pow *Ethash) verify(hash common.Hash, mixDigest common.Hash, difficulty *big.Int, blockNum uint64, nonce uint64) bool {
 	// Make sure the block num is valid
 	if blockNum >= epochLength*2048 {
-		powlogger.Infoln(fmt.Sprintf("Block number exceeds limit, invalid (value is %v, limit is %v)",
+		glog.V(logger.Info).Infoln(fmt.Sprintf("Block number exceeds limit, invalid (value is %v, limit is %v)",
 			blockNum, epochLength*2048))
 		return false
 	}
 
 	// First check: make sure header, mixDigest, nonce are correct without hitting the cache
 	// This is to prevent DOS attacks
-	chash := (*C.uint8_t)(unsafe.Pointer(&hash[0]))
+	chash := (*C.ethash_blockhash_t)(unsafe.Pointer(&hash[0]))
 	cnonce := C.uint64_t(nonce)
 	target := new(big.Int).Div(minDifficulty, difficulty)
 
@@ -387,7 +389,7 @@ func (pow *Ethash) verify(hash common.Hash, mixDigest common.Hash, difficulty *b
 		// If we can't make the params for some reason, this block is invalid
 		pAc, err = makeParamsAndCache(pow.chainManager, blockNum+1)
 		if err != nil {
-			powlogger.Infoln("big fucking eror", err)
+			glog.V(logger.Info).Infoln("big fucking eror", err)
 			return false
 		}
 	} else {
@@ -401,7 +403,7 @@ func (pow *Ethash) verify(hash common.Hash, mixDigest common.Hash, difficulty *b
 
 	C.ethash_light(ret, pAc.cache, pAc.params, chash, cnonce)
 
-	result := common.Bytes2Big(C.GoBytes(unsafe.Pointer(&ret.result[0]), C.int(32)))
+	result := common.Bytes2Big(C.GoBytes(unsafe.Pointer(&ret.result), C.int(32)))
 	return result.Cmp(target) <= 0
 }
 
@@ -417,7 +419,7 @@ func (pow *Ethash) FullHash(nonce uint64, miningHash []byte) []byte {
 	pow.UpdateDAG()
 	pow.dagMutex.Lock()
 	defer pow.dagMutex.Unlock()
-	cMiningHash := (*C.uint8_t)(unsafe.Pointer(&miningHash[0]))
+	cMiningHash := (*C.ethash_blockhash_t)(unsafe.Pointer(&miningHash[0]))
 	cnonce := C.uint64_t(nonce)
 	ret := new(C.ethash_return_value)
 	// pow.hash is the output/return of ethash_full
@@ -427,7 +429,7 @@ func (pow *Ethash) FullHash(nonce uint64, miningHash []byte) []byte {
 }
 
 func (pow *Ethash) LightHash(nonce uint64, miningHash []byte) []byte {
-	cMiningHash := (*C.uint8_t)(unsafe.Pointer(&miningHash[0]))
+	cMiningHash := (*C.ethash_blockhash_t)(unsafe.Pointer(&miningHash[0]))
 	cnonce := C.uint64_t(nonce)
 	ret := new(C.ethash_return_value)
 	C.ethash_light(ret, pow.paramsAndCache.cache, pow.paramsAndCache.params, cMiningHash, cnonce)
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/setup.py b/Godeps/_workspace/src/github.com/ethereum/ethash/setup.py
index 29d6ad6d2..6a6b93839 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/setup.py
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/setup.py
@@ -1,33 +1,34 @@
 #!/usr/bin/env python
 from distutils.core import setup, Extension
- 
-pyethash = Extension('pyethash', 
-        sources = [
-            'src/python/core.c', 
-            'src/libethash/util.c', 
-            'src/libethash/internal.c',
-            'src/libethash/sha3.c'],
-        depends = [
-            'src/libethash/ethash.h',
-            'src/libethash/compiler.h',
-            'src/libethash/data_sizes.h',
-            'src/libethash/endian.h',
-            'src/libethash/ethash.h',
-            'src/libethash/fnv.h',
-            'src/libethash/internal.h',
-            'src/libethash/sha3.h',
-            'src/libethash/util.h'
-            ],
-        extra_compile_args = ["-Isrc/", "-std=gnu99", "-Wall"])
- 
-setup (
-       name = 'pyethash',
-       author = "Matthew Wampler-Doty",
-       author_email = "matthew.wampler.doty@gmail.com",
-       license = 'GPL',
-       version = '23',
-       url = 'https://github.com/ethereum/ethash',
-       download_url = 'https://github.com/ethereum/ethash/tarball/v23',
-       description = 'Python wrappers for ethash, the ethereum proof of work hashing function',
-       ext_modules = [pyethash],
-      )
+
+pyethash = Extension('pyethash',
+                     sources=[
+                         'src/python/core.c',
+                         'src/libethash/util.c',
+                         'src/libethash/internal.c',
+                         'src/libethash/sha3.c'],
+                     depends=[
+                         'src/libethash/ethash.h',
+                         'src/libethash/compiler.h',
+                         'src/libethash/data_sizes.h',
+                         'src/libethash/endian.h',
+                         'src/libethash/ethash.h',
+                         'src/libethash/fnv.h',
+                         'src/libethash/internal.h',
+                         'src/libethash/sha3.h',
+                         'src/libethash/util.h'
+                     ],
+                     extra_compile_args=["-Isrc/", "-std=gnu99", "-Wall"])
+
+setup(
+    name='pyethash',
+    author="Matthew Wampler-Doty",
+    author_email="matthew.wampler.doty@gmail.com",
+    license='GPL',
+    version='0.1.23',
+    url='https://github.com/ethereum/ethash',
+    download_url='https://github.com/ethereum/ethash/tarball/v23',
+    description=('Python wrappers for ethash, the ethereum proof of work'
+                 'hashing function'),
+    ext_modules=[pyethash],
+)
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/benchmark/benchmark.cpp b/Godeps/_workspace/src/github.com/ethereum/ethash/src/benchmark/benchmark.cpp
index 17e9e1b7a..2635c8038 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/benchmark/benchmark.cpp
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/benchmark/benchmark.cpp
@@ -106,10 +106,11 @@ extern "C" int main(void)
 	//params.full_size = 8209 * 4096;	// 8MBish;
 	//params.cache_size = 8209*4096;
 	//params.cache_size = 2053*4096;
-	uint8_t seed[32], previous_hash[32];
+	ethash_blockhash_t seed;
+	ethash_blockhash_t previous_hash;
 
-	memcpy(seed, hexStringToBytes("9410b944535a83d9adf6bbdcc80e051f30676173c16ca0d32d6f1263fc246466").data(), 32);
-	memcpy(previous_hash, hexStringToBytes("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470").data(), 32);
+	memcpy(&seed, hexStringToBytes("9410b944535a83d9adf6bbdcc80e051f30676173c16ca0d32d6f1263fc246466").data(), 32);
+	memcpy(&previous_hash, hexStringToBytes("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470").data(), 32);
 	
 	// allocate page aligned buffer for dataset
 #ifdef FULL
@@ -128,9 +129,9 @@ extern "C" int main(void)
 		ethash_mkcache(&cache, &params, seed);
 		auto time = std::chrono::duration_cast<std::chrono::milliseconds>(high_resolution_clock::now() - startTime).count();
 
-		uint8_t cache_hash[32];
-		SHA3_256(cache_hash, (uint8_t const*)cache_mem, params.cache_size);
-		debugf("ethash_mkcache: %ums, sha3: %s\n", (unsigned)time, bytesToHexString(cache_hash,sizeof(cache_hash)).data());
+		ethash_blockhash_t cache_hash;
+		SHA3_256(&cache_hash, (uint8_t const*)cache_mem, params.cache_size);
+		debugf("ethash_mkcache: %ums, sha3: %s\n", (unsigned)((time*1000)/CLOCKS_PER_SEC), bytesToHexString(cache_hash,sizeof(cache_hash)).data());
 
 		// print a couple of test hashes
 		{
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.cpp b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.cpp
index e668f0622..bf7bb2128 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.cpp
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.cpp
@@ -54,15 +54,7 @@ ethash_cl_miner::ethash_cl_miner()
 {
 }
 
-void ethash_cl_miner::finish()
-{
-	if (m_queue())
-	{
-		m_queue.finish();
-	}
-}
-
-bool ethash_cl_miner::init(ethash_params const& params, const uint8_t seed[32], unsigned workgroup_size)
+bool ethash_cl_miner::init(ethash_params const& params, ethash_blockhash_t const *seed, unsigned workgroup_size)
 {
 	// store params
 	m_params = params;
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.h
index 7889989e3..af614b3e4 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash-cl/ethash_cl_miner.h
@@ -19,7 +19,7 @@ public:
 public:
 	ethash_cl_miner();
 
-	bool init(ethash_params const& params, const uint8_t seed[32], unsigned workgroup_size = 64);
+	bool init(ethash_params const& params, ethash_blockhash_t const *seed, unsigned workgroup_size = 64);
 
 	void finish();
 	void hash(uint8_t* ret, uint8_t const* header, uint64_t nonce, unsigned count);
@@ -42,4 +42,4 @@ private:
 	cl::Buffer m_search_buf[c_num_buffers];
 	unsigned m_workgroup_size;
 	bool m_opencl_1_1;
-};
\ No newline at end of file
+};
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/ethash.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/ethash.h
index eb3097307..fad964449 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/ethash.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/ethash.h
@@ -47,9 +47,26 @@ typedef struct ethash_params {
 	uint64_t cache_size;              // Size of compute cache (in bytes, multiple of node size (64)).
 } ethash_params;
 
+/// Type of a blockhash
+typedef struct ethash_blockhash { uint8_t b[32]; } ethash_blockhash_t;
+static inline uint8_t ethash_blockhash_get(ethash_blockhash_t const* hash, unsigned int i)
+{
+    return hash->b[i];
+}
+
+static inline void ethash_blockhash_set(ethash_blockhash_t *hash, unsigned int i, uint8_t v)
+{
+    hash->b[i] = v;
+}
+
+static inline void ethash_blockhash_reset(ethash_blockhash_t *hash)
+{
+    memset(hash, 0, 32);
+}
+
 typedef struct ethash_return_value {
-	uint8_t result[32];
-	uint8_t mix_hash[32];
+    ethash_blockhash_t result;
+    ethash_blockhash_t mix_hash;
 } ethash_return_value;
 
 uint64_t ethash_get_datasize(const uint32_t block_number);
@@ -65,58 +82,68 @@ typedef struct ethash_cache {
 	void *mem;
 } ethash_cache;
 
-void ethash_mkcache(ethash_cache *cache, ethash_params const *params, const uint8_t seed[32]);
+void ethash_mkcache(ethash_cache *cache, ethash_params const *params, ethash_blockhash_t const *seed);
 void ethash_compute_full_data(void *mem, ethash_params const *params, ethash_cache const *cache);
-void ethash_full(ethash_return_value *ret, void const *full_mem, ethash_params const *params, const uint8_t header_hash[32], const uint64_t nonce);
-void ethash_light(ethash_return_value *ret, ethash_cache const *cache, ethash_params const *params, const uint8_t header_hash[32], const uint64_t nonce);
-void ethash_get_seedhash(uint8_t seedhash[32], const uint32_t block_number);
+void ethash_full(ethash_return_value *ret,
+                 void const *full_mem,
+                 ethash_params const *params,
+                 ethash_blockhash_t const *header_hash,
+                 const uint64_t nonce);
+void ethash_light(ethash_return_value *ret,
+                  ethash_cache const *cache,
+                  ethash_params const *params,
+                  ethash_blockhash_t const *header_hash,
+                  const uint64_t nonce);
+void ethash_get_seedhash(ethash_blockhash_t *seedhash, const uint32_t block_number);
 
-static inline void ethash_prep_light(void *cache, ethash_params const *params, const uint8_t seed[32]) {
-	ethash_cache c;
-	c.mem = cache;
-	ethash_mkcache(&c, params, seed);
+static inline void ethash_prep_light(void *cache, ethash_params const *params, ethash_blockhash_t const* seed)
+{
+    ethash_cache c;
+    c.mem = cache;
+    ethash_mkcache(&c, params, seed);
 }
 
-static inline void ethash_compute_light(ethash_return_value *ret, void const *cache, ethash_params const *params, const uint8_t header_hash[32], const uint64_t nonce) {
-	ethash_cache c;
-	c.mem = (void *) cache;
-	ethash_light(ret, &c, params, header_hash, nonce);
+static inline void ethash_compute_light(ethash_return_value *ret, void const *cache, ethash_params const *params, ethash_blockhash_t const *header_hash, const uint64_t nonce)
+{
+    ethash_cache c;
+    c.mem = (void *) cache;
+    ethash_light(ret, &c, params, header_hash, nonce);
 }
 
-static inline void ethash_prep_full(void *full, ethash_params const *params, void const *cache) {
-	ethash_cache c;
-	c.mem = (void *) cache;
-	ethash_compute_full_data(full, params, &c);
+static inline void ethash_prep_full(void *full, ethash_params const *params, void const *cache)
+{
+    ethash_cache c;
+    c.mem = (void *) cache;
+    ethash_compute_full_data(full, params, &c);
 }
 
-static inline void ethash_compute_full(ethash_return_value *ret, void const *full, ethash_params const *params, const uint8_t header_hash[32], const uint64_t nonce) {
-	ethash_full(ret, full, params, header_hash, nonce);
+static inline void ethash_compute_full(ethash_return_value *ret,
+                                       void const *full,
+                                       ethash_params const *params,
+                                       ethash_blockhash_t const *header_hash,
+                                       const uint64_t nonce)
+{
+    ethash_full(ret, full, params, header_hash, nonce);
 }
 
-/// @brief Compare two s256-bit big-endian values.
-/// @returns 1 if @a a is less than or equal to @a b, 0 otherwise.
-/// Both parameters are 256-bit big-endian values.
-static inline int ethash_leq_be256(const uint8_t a[32], const uint8_t b[32]) {
-	// Boundary is big endian
-	for (int i = 0; i < 32; i++) {
-		if (a[i] == b[i])
-			continue;
-		return a[i] < b[i];
-	}
-	return 1;
+// Returns if hash is less than or equal to difficulty
+static inline int ethash_check_difficulty(ethash_blockhash_t const *hash,
+                                          ethash_blockhash_t const *difficulty)
+{
+    // Difficulty is big endian
+    for (int i = 0; i < 32; i++) {
+        if (ethash_blockhash_get(hash, i) == ethash_blockhash_get(difficulty, i)) {
+            continue;
+        }
+        return ethash_blockhash_get(hash, i) < ethash_blockhash_get(difficulty, i);
+    }
+    return 1;
 }
 
-/// Perofrms a cursory check on the validity of the nonce.
-/// @returns 1 if the nonce may possibly be valid for the given header_hash & boundary.
-/// @p boundary equivalent to 2 ^ 256 / block_difficulty, represented as a 256-bit big-endian.
-int ethash_preliminary_check_boundary(
-	const uint8_t header_hash[32],
-	const uint64_t nonce,
-	const uint8_t mix_hash[32],
-	const uint8_t boundary[32]);
-
-#define ethash_quick_check_difficulty ethash_preliminary_check_boundary
-#define ethash_check_difficulty ethash_leq_be256
+int ethash_quick_check_difficulty(ethash_blockhash_t const *header_hash,
+                                  const uint64_t nonce,
+                                  ethash_blockhash_t const *mix_hash,
+                                  ethash_blockhash_t const *difficulty);
 
 #ifdef __cplusplus
 }
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c
index ae9b95065..5009d52f5 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.c
@@ -50,14 +50,14 @@ uint64_t ethash_get_cachesize(const uint32_t block_number) {
 // Follows Sergio's "STRICT MEMORY HARD HASHING FUNCTIONS" (2014)
 // https://bitslog.files.wordpress.com/2013/12/memohash-v0-3.pdf
 // SeqMemoHash(s, R, N)
-void static ethash_compute_cache_nodes(
-        node *const nodes,
-        ethash_params const *params,
-        const uint8_t seed[32]) {
+void static ethash_compute_cache_nodes(node *const nodes,
+                                       ethash_params const *params,
+                                       ethash_blockhash_t const* seed)
+{
     assert((params->cache_size % sizeof(node)) == 0);
     uint32_t const num_nodes = (uint32_t) (params->cache_size / sizeof(node));
 
-    SHA3_512(nodes[0].bytes, seed, 32);
+    SHA3_512(nodes[0].bytes, (uint8_t*)seed, 32);
 
     for (unsigned i = 1; i != num_nodes; ++i) {
         SHA3_512(nodes[i].bytes, nodes[i - 1].bytes, 64);
@@ -84,20 +84,19 @@ void static ethash_compute_cache_nodes(
 #endif
 }
 
-void ethash_mkcache(
-        ethash_cache *cache,
-        ethash_params const *params,
-        const uint8_t seed[32]) {
+void ethash_mkcache(ethash_cache *cache,
+                    ethash_params const *params,
+                    ethash_blockhash_t const* seed)
+{
     node *nodes = (node *) cache->mem;
     ethash_compute_cache_nodes(nodes, params, seed);
 }
 
-void ethash_calculate_dag_item(
-        node *const ret,
-        const unsigned node_index,
-        const struct ethash_params *params,
-        const struct ethash_cache *cache) {
-
+void ethash_calculate_dag_item(node *const ret,
+                               const unsigned node_index,
+                               const struct ethash_params *params,
+                               const struct ethash_cache *cache)
+{
     uint32_t num_parent_nodes = (uint32_t) (params->cache_size / sizeof(node));
     node const *cache_nodes = (node const *) cache->mem;
     node const *init = &cache_nodes[node_index % num_parent_nodes];
@@ -161,13 +160,13 @@ void ethash_compute_full_data(
     }
 }
 
-static void ethash_hash(
-        ethash_return_value *ret,
-        node const *full_nodes,
-        ethash_cache const *cache,
-        ethash_params const *params,
-        const uint8_t header_hash[32],
-        const uint64_t nonce) {
+static void ethash_hash(ethash_return_value *ret,
+                        node const *full_nodes,
+                        ethash_cache const *cache,
+                        ethash_params const *params,
+                        ethash_blockhash_t const *header_hash,
+                        const uint64_t nonce)
+{
 
     assert((params->full_size % MIX_WORDS) == 0);
 
@@ -251,16 +250,16 @@ static void ethash_hash(
     }
 #endif
 
-    memcpy(ret->mix_hash, mix->bytes, 32);
+    memcpy(&ret->mix_hash, mix->bytes, 32);
     // final Keccak hash
-    SHA3_256(ret->result, s_mix->bytes, 64 + 32); // Keccak-256(s + compressed_mix)
+    SHA3_256(&ret->result, s_mix->bytes, 64 + 32); // Keccak-256(s + compressed_mix)
 }
 
-void ethash_quick_hash(
-        uint8_t return_hash[32],
-        const uint8_t header_hash[32],
-        const uint64_t nonce,
-        const uint8_t mix_hash[32]) {
+void ethash_quick_hash(ethash_blockhash_t *return_hash,
+                       ethash_blockhash_t const *header_hash,
+                       const uint64_t nonce,
+                       ethash_blockhash_t const *mix_hash)
+{
 
     uint8_t buf[64 + 32];
     memcpy(buf, header_hash, 32);
@@ -273,28 +272,39 @@ void ethash_quick_hash(
     SHA3_256(return_hash, buf, 64 + 32);
 }
 
-void ethash_get_seedhash(uint8_t seedhash[32], const uint32_t block_number) {
-    memset(seedhash, 0, 32);
+void ethash_get_seedhash(ethash_blockhash_t *seedhash, const uint32_t block_number)
+{
+    ethash_blockhash_reset(seedhash);
     const uint32_t epochs = block_number / EPOCH_LENGTH;
     for (uint32_t i = 0; i < epochs; ++i)
-        SHA3_256(seedhash, seedhash, 32);
+        SHA3_256(seedhash, (uint8_t*)seedhash, 32);
 }
 
-int ethash_preliminary_check_boundary(
-        const uint8_t header_hash[32],
-        const uint64_t nonce,
-        const uint8_t mix_hash[32],
-		const uint8_t difficulty[32]) {
+int ethash_quick_check_difficulty(ethash_blockhash_t const *header_hash,
+                                  const uint64_t nonce,
+                                  ethash_blockhash_t const *mix_hash,
+                                  ethash_blockhash_t const *difficulty)
+{
 
-	uint8_t return_hash[32];
-    ethash_quick_hash(return_hash, header_hash, nonce, mix_hash);
-	return ethash_leq_be256(return_hash, difficulty);
+    ethash_blockhash_t return_hash;
+    ethash_quick_hash(&return_hash, header_hash, nonce, mix_hash);
+    return ethash_check_difficulty(&return_hash, difficulty);
 }
 
-void ethash_full(ethash_return_value *ret, void const *full_mem, ethash_params const *params, const uint8_t previous_hash[32], const uint64_t nonce) {
-    ethash_hash(ret, (node const *) full_mem, NULL, params, previous_hash, nonce);
+void ethash_full(ethash_return_value *ret,
+                 void const *full_mem,
+                 ethash_params const *params,
+                 ethash_blockhash_t const *header_hash,
+                 const uint64_t nonce)
+{
+    ethash_hash(ret, (node const *) full_mem, NULL, params, header_hash, nonce);
 }
 
-void ethash_light(ethash_return_value *ret, ethash_cache const *cache, ethash_params const *params, const uint8_t previous_hash[32], const uint64_t nonce) {
-    ethash_hash(ret, NULL, cache, params, previous_hash, nonce);
+void ethash_light(ethash_return_value *ret,
+                  ethash_cache const *cache,
+                  ethash_params const *params,
+                  ethash_blockhash_t const *header_hash,
+                  const uint64_t nonce)
+{
+    ethash_hash(ret, NULL, cache, params, header_hash, nonce);
 }
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h
index ddd06e8f4..1e19cd1fd 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/internal.h
@@ -30,19 +30,16 @@ typedef union node {
 
 } node;
 
-void ethash_calculate_dag_item(
-        node *const ret,
-        const unsigned node_index,
-        ethash_params const *params,
-        ethash_cache const *cache
-);
+void ethash_calculate_dag_item(node *const ret,
+                               const unsigned node_index,
+                               ethash_params const *params,
+                               ethash_cache const *cache);
 
-void ethash_quick_hash(
-        uint8_t return_hash[32],
-        const uint8_t header_hash[32],
-        const uint64_t nonce,
-        const uint8_t mix_hash[32]);
+void ethash_quick_hash(ethash_blockhash_t *return_hash,
+                       ethash_blockhash_t const *header_hash,
+                       const uint64_t nonce,
+                       ethash_blockhash_t const *mix_hash);
 
 #ifdef __cplusplus
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/io.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/io.h
index dd611754d..8cf8b69bf 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/io.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/io.h
@@ -28,8 +28,6 @@
 extern "C" {
 #endif
 
-typedef struct ethash_blockhash { uint8_t b[32]; } ethash_blockhash_t;
-
 static const char DAG_FILE_NAME[] = "full";
 static const char DAG_MEMO_NAME[] = "full.info";
 // MSVC thinks that "static const unsigned int" is not a compile time variable. Sorry for the #define :(
@@ -54,6 +52,7 @@ enum ethash_io_rc {
  * @return               For possible return values @see enum ethash_io_rc
  */
 enum ethash_io_rc ethash_io_prepare(char const *dirname, ethash_blockhash_t seedhash);
+
 /**
  * Fully computes data and writes it to the file on disk.
  *
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3.h
index 36a0a5301..84dca241b 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3.h
@@ -8,20 +8,24 @@ extern "C" {
 #include <stdint.h>
 #include <stdlib.h>
 
+struct ethash_blockhash;
+
 #define decsha3(bits) \
   int sha3_##bits(uint8_t*, size_t, const uint8_t*, size_t);
 
 decsha3(256)
 decsha3(512)
 
-static inline void SHA3_256(uint8_t * const ret, uint8_t const *data, const size_t size) {
-    sha3_256(ret, 32, data, size);
+static inline void SHA3_256(struct ethash_blockhash const* ret, uint8_t const *data, const size_t size)
+{
+    sha3_256((uint8_t*)ret, 32, data, size);
 }
 
-static inline void SHA3_512(uint8_t * const ret, uint8_t const *data, const size_t size) {
+static inline void SHA3_512(uint8_t *ret, uint8_t const *data, const size_t size)
+{
     sha3_512(ret, 64, data, size);
 }
 
 #ifdef __cplusplus
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.cpp b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.cpp
index 6cbbcad8f..e4d8b1855 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.cpp
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.cpp
@@ -19,16 +19,17 @@
 * @author Tim Hughes <tim@twistedfury.com>
 * @date 2015
 */
-
 #include <stdint.h>
 #include <cryptopp/sha3.h>
 
 extern "C" {
-void SHA3_256(uint8_t *const ret, const uint8_t *data, size_t size) {
-  CryptoPP::SHA3_256().CalculateDigest(ret, data, size);
+struct ethash_blockhash;
+typedef struct ethash_blockhash ethash_blockhash_t;
+void SHA3_256(ethash_blockhash_t const* ret, const uint8_t *data, size_t size) {
+    CryptoPP::SHA3_256().CalculateDigest((uint8_t*)ret, data, size);
 }
 
 void SHA3_512(uint8_t *const ret, const uint8_t *data, size_t size) {
   CryptoPP::SHA3_512().CalculateDigest(ret, data, size);
 }
-}
\ No newline at end of file
+}
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.h b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.h
index f910960e1..6b257b87c 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.h
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/libethash/sha3_cryptopp.h
@@ -2,14 +2,18 @@
 
 #include "compiler.h"
 #include <stdint.h>
+#include <stdlib.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-void SHA3_256(uint8_t *const ret, const uint8_t *data, size_t size);
+struct ethash_blockhash;
+typedef struct ethash_blockhash ethash_blockhash_t;
+
+void SHA3_256(ethash_blockhash_t *const ret, const uint8_t *data, size_t size);
 void SHA3_512(uint8_t *const ret, const uint8_t *data, size_t size);
 
 #ifdef __cplusplus
 }
-#endif
\ No newline at end of file
+#endif
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/src/python/core.c b/Godeps/_workspace/src/github.com/ethereum/ethash/src/python/core.c
index 1ad973a87..9024bd584 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/src/python/core.c
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/src/python/core.c
@@ -69,7 +69,7 @@ mkcache_bytes(PyObject *self, PyObject *args) {
     params.cache_size = (size_t) cache_size;
     ethash_cache cache;
     cache.mem = malloc(cache_size);
-    ethash_mkcache(&cache, &params, (uint8_t *) seed);
+    ethash_mkcache(&cache, &params, (ethash_blockhash_t *) seed);
     PyObject * val = Py_BuildValue(PY_STRING_FORMAT, cache.mem, cache_size);
     free(cache.mem);
     return val;
@@ -114,28 +114,25 @@ calc_dataset_bytes(PyObject *self, PyObject *args) {
 // hashimoto_light(full_size, cache, header, nonce)
 static PyObject *
 hashimoto_light(PyObject *self, PyObject *args) {
-    char *cache_bytes, *header;
+    char *cache_bytes;
+    char *header;
     unsigned long full_size;
     unsigned long long nonce;
     int cache_size, header_size;
-
     if (!PyArg_ParseTuple(args, "k" PY_STRING_FORMAT PY_STRING_FORMAT "K", &full_size, &cache_bytes, &cache_size, &header, &header_size, &nonce))
         return 0;
-
     if (full_size % MIX_WORDS != 0) {
         char error_message[1024];
         sprintf(error_message, "The size of data set must be a multiple of %i bytes (was %lu)", MIX_WORDS, full_size);
         PyErr_SetString(PyExc_ValueError, error_message);
         return 0;
     }
-
     if (cache_size % HASH_BYTES != 0) {
         char error_message[1024];
         sprintf(error_message, "The size of the cache must be a multiple of %i bytes (was %i)", HASH_BYTES, cache_size);
         PyErr_SetString(PyExc_ValueError, error_message);
         return 0;
     }
-
     if (header_size != 32) {
         char error_message[1024];
         sprintf(error_message, "Seed must be 32 bytes long (was %i)", header_size);
@@ -143,23 +140,23 @@ hashimoto_light(PyObject *self, PyObject *args) {
         return 0;
     }
 
-
     ethash_return_value out;
     ethash_params params;
     params.cache_size = (size_t) cache_size;
     params.full_size = (size_t) full_size;
     ethash_cache cache;
     cache.mem = (void *) cache_bytes;
-    ethash_light(&out, &cache, &params, (uint8_t *) header, nonce);
+    ethash_light(&out, &cache, &params, (ethash_blockhash_t *) header, nonce);
     return Py_BuildValue("{" PY_CONST_STRING_FORMAT ":" PY_STRING_FORMAT "," PY_CONST_STRING_FORMAT ":" PY_STRING_FORMAT "}",
-            "mix digest", out.mix_hash, 32,
-            "result", out.result, 32);
+                         "mix digest", &out.mix_hash, 32,
+                         "result", &out.result, 32);
 }
 
 // hashimoto_full(dataset, header, nonce)
 static PyObject *
 hashimoto_full(PyObject *self, PyObject *args) {
-    char *full_bytes, *header;
+    char *full_bytes;
+    char *header;
     unsigned long long nonce;
     int full_size, header_size;
 
@@ -184,16 +181,18 @@ hashimoto_full(PyObject *self, PyObject *args) {
     ethash_return_value out;
     ethash_params params;
     params.full_size = (size_t) full_size;
-    ethash_full(&out, (void *) full_bytes, &params, (uint8_t *) header, nonce);
+    ethash_full(&out, (void *) full_bytes, &params, (ethash_blockhash_t *) header, nonce);
     return Py_BuildValue("{" PY_CONST_STRING_FORMAT ":" PY_STRING_FORMAT ", " PY_CONST_STRING_FORMAT ":" PY_STRING_FORMAT "}",
-            "mix digest", out.mix_hash, 32,
-            "result", out.result, 32);
+                         "mix digest", &out.mix_hash, 32,
+                         "result", &out.result, 32);
 }
 
 // mine(dataset_bytes, header, difficulty_bytes)
 static PyObject *
 mine(PyObject *self, PyObject *args) {
-    char *full_bytes, *header, *difficulty;
+    char *full_bytes;
+    char *header;
+    char *difficulty;
     srand(time(0));
     uint64_t nonce = ((uint64_t) rand()) << 32 | rand();
     int full_size, header_size, difficulty_size;
@@ -228,13 +227,13 @@ mine(PyObject *self, PyObject *args) {
 
     // TODO: Multi threading?
     do {
-        ethash_full(&out, (void *) full_bytes, &params, (const uint8_t *) header, nonce++);
+        ethash_full(&out, (void *) full_bytes, &params, (const ethash_blockhash_t *) header, nonce++);
         // TODO: disagrees with the spec https://github.com/ethereum/wiki/wiki/Ethash#mining
-    } while (!ethash_check_difficulty(out.result, (const uint8_t *) difficulty));
+    } while (!ethash_check_difficulty(&out.result, (const ethash_blockhash_t *) difficulty));
 
     return Py_BuildValue("{" PY_CONST_STRING_FORMAT ":" PY_STRING_FORMAT ", " PY_CONST_STRING_FORMAT ":" PY_STRING_FORMAT ", " PY_CONST_STRING_FORMAT ":K}",
-            "mix digest", out.mix_hash, 32,
-            "result", out.result, 32,
+            "mix digest", &out.mix_hash, 32,
+            "result", &out.result, 32,
             "nonce", nonce);
 }
 
@@ -251,9 +250,9 @@ get_seedhash(PyObject *self, PyObject *args) {
         PyErr_SetString(PyExc_ValueError, error_message);
         return 0;
     }
-    uint8_t seedhash[32];
-    ethash_get_seedhash(seedhash, block_number);
-    return Py_BuildValue(PY_STRING_FORMAT, (char *) seedhash, 32);
+    ethash_blockhash_t seedhash;
+    ethash_get_seedhash(&seedhash, block_number);
+    return Py_BuildValue(PY_STRING_FORMAT, (char *) &seedhash, 32);
 }
 
 static PyMethodDef PyethashMethods[] =
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/test/c/test.cpp b/Godeps/_workspace/src/github.com/ethereum/ethash/test/c/test.cpp
index 904f4f74c..ffe8d53f3 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/test/c/test.cpp
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/test/c/test.cpp
@@ -37,6 +37,10 @@ std::string bytesToHexString(const uint8_t *str, const uint64_t s) {
     return ret.str();
 }
 
+std::string blockhashToHexString(ethash_blockhash_t *hash) {
+    return bytesToHexString((uint8_t*)hash, 32);
+}
+
 BOOST_AUTO_TEST_CASE(fnv_hash_check) {
     uint32_t x = 1235U;
     const uint32_t
@@ -52,12 +56,13 @@ BOOST_AUTO_TEST_CASE(fnv_hash_check) {
 }
 
 BOOST_AUTO_TEST_CASE(SHA256_check) {
-    uint8_t input[32], out[32];
-    memcpy(input, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~", 32);
-    SHA3_256(out, input, 32);
+    ethash_blockhash_t input;
+    ethash_blockhash_t out;
+    memcpy(&input, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~", 32);
+    SHA3_256(&out, (uint8_t*)&input, 32);
     const std::string
             expected = "2b5ddf6f4d21c23de216f44d5e4bdc68e044b71897837ea74c83908be7037cd7",
-            actual = bytesToHexString(out, 32);
+        actual = bytesToHexString((uint8_t*)&out, 32);
     BOOST_REQUIRE_MESSAGE(expected == actual,
             "\nexpected: " << expected.c_str() << "\n"
                     << "actual: " << actual.c_str() << "\n");
@@ -104,23 +109,26 @@ BOOST_AUTO_TEST_CASE(ethash_params_init_genesis_calcifide_check) {
 
 BOOST_AUTO_TEST_CASE(light_and_full_client_checks) {
     ethash_params params;
-    uint8_t seed[32], hash[32], difficulty[32];
-    ethash_return_value light_out, full_out;
-    memcpy(seed, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~", 32);
-    memcpy(hash, "~~~X~~~~~~~~~~~~~~~~~~~~~~~~~~~~", 32);
+    ethash_blockhash_t seed;
+    ethash_blockhash_t hash;
+    ethash_blockhash_t difficulty;
+    ethash_return_value light_out;
+    ethash_return_value full_out;
+    memcpy(&seed, "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~", 32);
+    memcpy(&hash, "~~~X~~~~~~~~~~~~~~~~~~~~~~~~~~~~", 32);
 
     // Set the difficulty
-    difficulty[0] = 197;
-    difficulty[1] = 90;
+    ethash_blockhash_set(&difficulty, 0, 197);
+    ethash_blockhash_set(&difficulty, 1, 90);
     for (int i = 2; i < 32; i++)
-        difficulty[i] = (uint8_t) 255;
+        ethash_blockhash_set(&difficulty, i, 255);
 
     ethash_params_init(&params, 0);
     params.cache_size = 1024;
     params.full_size = 1024 * 32;
     ethash_cache cache;
     cache.mem = our_alloca(params.cache_size);
-    ethash_mkcache(&cache, &params, seed);
+    ethash_mkcache(&cache, &params, &seed);
     node *full_mem = (node *) our_alloca(params.full_size);
     ethash_compute_full_data(full_mem, &params, &cache);
 
@@ -164,78 +172,76 @@ BOOST_AUTO_TEST_CASE(light_and_full_client_checks) {
 
     {
         uint64_t nonce = 0x7c7c597c;
-        ethash_full(&full_out, full_mem, &params, hash, nonce);
-        ethash_light(&light_out, &cache, &params, hash, nonce);
+        ethash_full(&full_out, full_mem, &params, &hash, nonce);
+        ethash_light(&light_out, &cache, &params, &hash, nonce);
         const std::string
-                light_result_string = bytesToHexString(light_out.result, 32),
-                full_result_string = bytesToHexString(full_out.result, 32);
+                light_result_string = blockhashToHexString(&light_out.result),
+                full_result_string = blockhashToHexString(&full_out.result);
         BOOST_REQUIRE_MESSAGE(light_result_string == full_result_string,
                 "\nlight result: " << light_result_string.c_str() << "\n"
                         << "full result: " << full_result_string.c_str() << "\n");
         const std::string
-                light_mix_hash_string = bytesToHexString(light_out.mix_hash, 32),
-                full_mix_hash_string = bytesToHexString(full_out.mix_hash, 32);
+                light_mix_hash_string = blockhashToHexString(&light_out.mix_hash),
+                full_mix_hash_string = blockhashToHexString(&full_out.mix_hash);
         BOOST_REQUIRE_MESSAGE(full_mix_hash_string == light_mix_hash_string,
                 "\nlight mix hash: " << light_mix_hash_string.c_str() << "\n"
                         << "full mix hash: " << full_mix_hash_string.c_str() << "\n");
-        uint8_t check_hash[32];
-        ethash_quick_hash(check_hash, hash, nonce, full_out.mix_hash);
-        const std::string check_hash_string = bytesToHexString(check_hash, 32);
+        ethash_blockhash_t check_hash;
+        ethash_quick_hash(&check_hash, &hash, nonce, &full_out.mix_hash);
+        const std::string check_hash_string = blockhashToHexString(&check_hash);
         BOOST_REQUIRE_MESSAGE(check_hash_string == full_result_string,
                 "\ncheck hash string: " << check_hash_string.c_str() << "\n"
                         << "full result: " << full_result_string.c_str() << "\n");
     }
     {
-        ethash_full(&full_out, full_mem, &params, hash, 5);
+        ethash_full(&full_out, full_mem, &params, &hash, 5);
         std::string
-                light_result_string = bytesToHexString(light_out.result, 32),
-                full_result_string = bytesToHexString(full_out.result, 32);
+                light_result_string = blockhashToHexString(&light_out.result),
+                full_result_string = blockhashToHexString(&full_out.result);
 
         BOOST_REQUIRE_MESSAGE(light_result_string != full_result_string,
                 "\nlight result and full result should differ: " << light_result_string.c_str() << "\n");
 
-        ethash_light(&light_out, &cache, &params, hash, 5);
-        light_result_string = bytesToHexString(light_out.result, 32);
+        ethash_light(&light_out, &cache, &params, &hash, 5);
+        light_result_string = blockhashToHexString(&light_out.result);
         BOOST_REQUIRE_MESSAGE(light_result_string == full_result_string,
                 "\nlight result and full result should be the same\n"
                         << "light result: " << light_result_string.c_str() << "\n"
                         << "full result: " << full_result_string.c_str() << "\n");
         std::string
-                light_mix_hash_string = bytesToHexString(light_out.mix_hash, 32),
-                full_mix_hash_string = bytesToHexString(full_out.mix_hash, 32);
+                light_mix_hash_string = blockhashToHexString(&light_out.mix_hash),
+                full_mix_hash_string = blockhashToHexString(&full_out.mix_hash);
         BOOST_REQUIRE_MESSAGE(full_mix_hash_string == light_mix_hash_string,
                 "\nlight mix hash: " << light_mix_hash_string.c_str() << "\n"
                         << "full mix hash: " << full_mix_hash_string.c_str() << "\n");
-        BOOST_REQUIRE_MESSAGE(ethash_check_difficulty(full_out.result, difficulty),
+        BOOST_REQUIRE_MESSAGE(ethash_check_difficulty(&full_out.result, &difficulty),
                 "ethash_check_difficulty failed"
         );
-        BOOST_REQUIRE_MESSAGE(ethash_quick_check_difficulty(hash, 5U, full_out.mix_hash, difficulty),
+        BOOST_REQUIRE_MESSAGE(ethash_quick_check_difficulty(&hash, 5U, &full_out.mix_hash, &difficulty),
                 "ethash_quick_check_difficulty failed"
         );
     }
 }
 
 BOOST_AUTO_TEST_CASE(ethash_check_difficulty_check) {
-    uint8_t hash[32], target[32];
-    memset(hash, 0, 32);
-    memset(target, 0, 32);
-
-    memcpy(hash, "11111111111111111111111111111111", 32);
-    memcpy(target, "22222222222222222222222222222222", 32);
+    ethash_blockhash_t hash;
+    ethash_blockhash_t target;
+    memcpy(&hash, "11111111111111111111111111111111", 32);
+    memcpy(&target, "22222222222222222222222222222222", 32);
     BOOST_REQUIRE_MESSAGE(
-            ethash_check_difficulty(hash, target),
-            "\nexpected \"" << std::string((char *) hash, 32).c_str() << "\" to have the same or less difficulty than \"" << std::string((char *) target, 32).c_str() << "\"\n");
+            ethash_check_difficulty(&hash, &target),
+            "\nexpected \"" << std::string((char *) &hash, 32).c_str() << "\" to have the same or less difficulty than \"" << std::string((char *) &target, 32).c_str() << "\"\n");
     BOOST_REQUIRE_MESSAGE(
-            ethash_check_difficulty(hash, hash),
-            "\nexpected \"" << hash << "\" to have the same or less difficulty than \"" << hash << "\"\n");
-    memcpy(target, "11111111111111111111111111111112", 32);
+        ethash_check_difficulty(&hash, &hash), "");
+            // "\nexpected \"" << hash << "\" to have the same or less difficulty than \"" << hash << "\"\n");
+    memcpy(&target, "11111111111111111111111111111112", 32);
     BOOST_REQUIRE_MESSAGE(
-            ethash_check_difficulty(hash, target),
-            "\nexpected \"" << hash << "\" to have the same or less difficulty than \"" << target << "\"\n");
-    memcpy(target, "11111111111111111111111111111110", 32);
+        ethash_check_difficulty(&hash, &target), "");
+            // "\nexpected \"" << hash << "\" to have the same or less difficulty than \"" << target << "\"\n");
+    memcpy(&target, "11111111111111111111111111111110", 32);
     BOOST_REQUIRE_MESSAGE(
-            !ethash_check_difficulty(hash, target),
-            "\nexpected \"" << hash << "\" to have more difficulty than \"" << target << "\"\n");
+            !ethash_check_difficulty(&hash, &target), "");
+            // "\nexpected \"" << hash << "\" to have more difficulty than \"" << target << "\"\n");
 }
 
 BOOST_AUTO_TEST_CASE(test_ethash_dir_creation) {
@@ -256,7 +262,7 @@ BOOST_AUTO_TEST_CASE(test_ethash_dir_creation) {
 BOOST_AUTO_TEST_CASE(test_ethash_io_write_files_are_created) {
     ethash_blockhash_t seedhash;
     static const int blockn = 0;
-    ethash_get_seedhash((uint8_t*)&seedhash, blockn);
+    ethash_get_seedhash(&seedhash, blockn);
     BOOST_REQUIRE_EQUAL(
         ETHASH_IO_MEMO_MISMATCH,
         ethash_io_prepare("./test_ethash_directory/", seedhash)
@@ -273,7 +279,7 @@ BOOST_AUTO_TEST_CASE(test_ethash_io_write_files_are_created) {
     params.cache_size = 1024;
     params.full_size = 1024 * 32;
     cache.mem = our_alloca(params.cache_size);
-    ethash_mkcache(&cache, &params, (uint8_t*)&seedhash);
+    ethash_mkcache(&cache, &params, &seedhash);
 
     BOOST_REQUIRE(
         ethash_io_write("./test_ethash_directory/", &params, seedhash, &cache, &data, &size)
@@ -290,7 +296,7 @@ BOOST_AUTO_TEST_CASE(test_ethash_io_write_files_are_created) {
 BOOST_AUTO_TEST_CASE(test_ethash_io_memo_file_match) {
     ethash_blockhash_t seedhash;
     static const int blockn = 0;
-    ethash_get_seedhash((uint8_t*)&seedhash, blockn);
+    ethash_get_seedhash(&seedhash, blockn);
     BOOST_REQUIRE_EQUAL(
         ETHASH_IO_MEMO_MISMATCH,
         ethash_io_prepare("./test_ethash_directory/", seedhash)
@@ -307,7 +313,7 @@ BOOST_AUTO_TEST_CASE(test_ethash_io_memo_file_match) {
     params.cache_size = 1024;
     params.full_size = 1024 * 32;
     cache.mem = our_alloca(params.cache_size);
-    ethash_mkcache(&cache, &params, (uint8_t*)&seedhash);
+    ethash_mkcache(&cache, &params, &seedhash);
 
     BOOST_REQUIRE(
         ethash_io_write("./test_ethash_directory/", &params, seedhash, &cache, &data, &size)
@@ -344,7 +350,7 @@ static std::vector<char> readFileIntoVector(char const* filename)
 BOOST_AUTO_TEST_CASE(test_ethash_io_memo_file_contents) {
     ethash_blockhash_t seedhash;
     static const int blockn = 0;
-    ethash_get_seedhash((uint8_t*)&seedhash, blockn);
+    ethash_get_seedhash(&seedhash, blockn);
     BOOST_REQUIRE_EQUAL(
         ETHASH_IO_MEMO_MISMATCH,
         ethash_io_prepare("./test_ethash_directory/", seedhash)
@@ -361,8 +367,8 @@ BOOST_AUTO_TEST_CASE(test_ethash_io_memo_file_contents) {
     params.cache_size = 1024;
     params.full_size = 1024 * 32;
     cache.mem = our_alloca(params.cache_size);
-    ethash_mkcache(&cache, &params, (uint8_t*)&seedhash);
-
+    ethash_mkcache(&cache, &params, &seedhash);
+    
     BOOST_REQUIRE(
         ethash_io_write("./test_ethash_directory/", &params, seedhash, &cache, &data, &size)
     );
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/test/python/test.sh b/Godeps/_workspace/src/github.com/ethereum/ethash/test/python/test.sh
index 95cea0215..05c66b550 100644
--- a/Godeps/_workspace/src/github.com/ethereum/ethash/test/python/test.sh
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/test/python/test.sh
@@ -3,6 +3,15 @@
 # Strict mode
 set -e
 
+if [ -x "$(which virtualenv2)" ] ; then
+   VIRTUALENV_EXEC=virtualenv2
+elif [ -x "$(which virtualenv)" ] ; then
+   VIRTUALENV_EXEC=virtualenv
+else
+   echo "Could not find a suitable version of virtualenv"
+   false
+fi
+
 SOURCE="${BASH_SOURCE[0]}"
 while [ -h "$SOURCE" ]; do
   DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
@@ -11,9 +20,11 @@ while [ -h "$SOURCE" ]; do
 done
 TEST_DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
 
-[ -d $TEST_DIR/python-virtual-env ] || virtualenv --system-site-packages $TEST_DIR/python-virtual-env
+[ -d $TEST_DIR/python-virtual-env ] || $VIRTUALENV_EXEC --system-site-packages $TEST_DIR/python-virtual-env
 source $TEST_DIR/python-virtual-env/bin/activate
 pip install -r $TEST_DIR/requirements.txt > /dev/null
+# force installation of nose in virtualenv even if existing in thereuser's system
+pip install nose -I
 pip install --upgrade --no-deps --force-reinstall -e $TEST_DIR/../..
 cd $TEST_DIR
 nosetests --with-doctest -v --nocapture