diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..e69de29bb
diff --git a/Makefile.am b/Makefile.am
index 3442b65e6..be0ec4312 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -86,7 +86,7 @@ $(OSX_APP)/Contents/PkgInfo:
 
 $(OSX_APP)/Contents/Resources/empty.lproj:
 	$(MKDIR_P) $(@D)
-	@touch $@ 
+	@touch $@
 
 $(OSX_APP)/Contents/Info.plist: $(OSX_PLIST)
 	$(MKDIR_P) $(@D)
@@ -242,7 +242,7 @@ cov: test_bitcoin.coverage/.dirstamp cov-zcash total.coverage/.dirstamp
 
 endif
 
-dist_bin_SCRIPTS = zcutil/fetch-params.sh
+dist_bin_SCRIPTS = #zcutil/fetch-params.sh
 dist_noinst_SCRIPTS = autogen.sh
 
 EXTRA_DIST = $(DIST_SHARE) test/functional/test_runner.py test/functional test/zcash $(DIST_CONTRIB) $(DIST_DOCS) $(WINDOWS_PACKAGING) $(OSX_PACKAGING) $(BIN_CHECKS)
@@ -327,4 +327,3 @@ clean-docs:
 clean-local: clean-docs
 	rm -rf coverage_percent.txt test_bitcoin.coverage/ zcash-gtest.coverage/ total.coverage/ test/tmp/ cache/ $(OSX_APP)
 	rm -rf test/functional/__pycache__ test/functional/test_framework/__pycache__ test/cache
-
diff --git a/src/Makefile.am b/src/Makefile.am
index 070fb3c1e..74e78a276 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -214,6 +214,7 @@ BITCOIN_CORE_H = \
   wallet/walletutil.h \
   wallet/coinselection.h \
   warnings.h \
+  zkaddr.h \
   zmq/zmqabstractnotifier.h \
   zmq/zmqconfig.h\
   zmq/zmqnotificationinterface.h \
@@ -366,6 +367,8 @@ libbitcoin_consensus_a_SOURCES = \
   prevector.h \
   primitives/block.cpp \
   primitives/block.h \
+  primitives/joinsplit.h \
+  primitives/joinsplit.cpp \
   primitives/transaction.cpp \
   primitives/transaction.h \
   pubkey.cpp \
@@ -410,6 +413,7 @@ libbitcoin_common_a_SOURCES = \
   script/sign.cpp \
   script/standard.cpp \
   warnings.cpp \
+  zkaddr.cpp \
   $(BITCOIN_CORE_H)
 
 # util: shared between all executables.
@@ -550,7 +554,7 @@ libzcash_a_CPPFLAGS = -DMULTICORE -fopenmp -fPIC -DBINARY_OUTPUT -DCURVE_ALT_BN1
 
 libzcash_a_CXXFLAGS = $(SAN_CXXFLAGS) $(HARDENED_CXXFLAGS) -fwrapv -fno-strict-aliasing
 
-libzcash_a_LIBADD = $(SAN_LDFLAGS) $(HARDENED_LDFLAGS)
+libzcash_a_LDFLAGS = $(SAN_LDFLAGS) $(HARDENED_LDFLAGS)
 
 libzcash_a_CPPFLAGS += -DMONTGOMERY_OUTPUT
 
@@ -638,7 +642,7 @@ endif
 
 if ENABLE_TESTS
 include Makefile.test.include
-include Makefile.gtest.include
+#include Makefile.gtest.include
 endif
 
 if ENABLE_BENCH
diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index c5b1c37bc..461af5931 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -77,6 +77,7 @@ BITCOIN_TESTS =\
   test/script_standard_tests.cpp \
   test/scriptnum_tests.cpp \
   test/serialize_tests.cpp \
+  test/sha256compress_tests.cpp \
   test/sighash_tests.cpp \
   test/sigopcount_tests.cpp \
   test/skiplist_tests.cpp \
diff --git a/src/Makefile.zcash.include b/src/Makefile.zcash.include
index 177931c88..1a1e726c3 100644
--- a/src/Makefile.zcash.include
+++ b/src/Makefile.zcash.include
@@ -24,5 +24,6 @@ zcash_CreateJoinSplit_LDADD = \
   $(LIBSNARK) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CRYPTO) \
+  $(LIBBITCOIN_CONSENSUS) \
   $(BOOST_LIBS) \
   $(LIBZCASH_LIBS)
diff --git a/src/base58.h b/src/base58.h
index 8f2833bec..902ac75ad 100644
--- a/src/base58.h
+++ b/src/base58.h
@@ -16,6 +16,7 @@
 
 #include <string>
 #include <vector>
+#include <support/allocators/zeroafterfree.h>
 
 /**
  * Encode a byte sequence as a base58-encoded string.
@@ -58,4 +59,34 @@ bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet);
  */
 bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet);
 
+/**
+ * Base class for all base58-encoded data
+ */
+class CBase58Data
+{
+protected:
+    //! the version byte(s)
+    std::vector<unsigned char> vchVersion;
+
+    //! the actually encoded data
+    typedef std::vector<unsigned char, zero_after_free_allocator<unsigned char> > vector_uchar;
+    vector_uchar vchData;
+
+    CBase58Data();
+    void SetData(const std::vector<unsigned char> &vchVersionIn, const void* pdata, size_t nSize);
+    void SetData(const std::vector<unsigned char> &vchVersionIn, const unsigned char *pbegin, const unsigned char *pend);
+
+public:
+    bool SetString(const char* psz, unsigned int nVersionBytes);
+    bool SetString(const std::string& str, unsigned int nVersionBytes);
+    std::string ToString() const;
+    int CompareTo(const CBase58Data& b58) const;
+
+    bool operator==(const CBase58Data& b58) const { return CompareTo(b58) == 0; }
+    bool operator<=(const CBase58Data& b58) const { return CompareTo(b58) <= 0; }
+    bool operator>=(const CBase58Data& b58) const { return CompareTo(b58) >= 0; }
+    bool operator< (const CBase58Data& b58) const { return CompareTo(b58) <  0; }
+    bool operator> (const CBase58Data& b58) const { return CompareTo(b58) >  0; }
+};
+
 #endif // BITCOIN_BASE58_H
diff --git a/src/chain.h b/src/chain.h
index 8e6ac8d82..4b3470a09 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -211,7 +211,7 @@ public:
     uint256 hashMerkleRoot;
     uint32_t nTime;
     uint32_t nBits;
-    uint32_t nNonce;
+    uint256 nNonce;
 
     //! (memory only) Sequential id assigned to distinguish order in which blocks are received.
     int32_t nSequenceId;
@@ -239,7 +239,7 @@ public:
         hashMerkleRoot = uint256();
         nTime          = 0;
         nBits          = 0;
-        nNonce         = 0;
+        nNonce         = uint256();
     }
 
     CBlockIndex()
diff --git a/src/crypto/common.h b/src/crypto/common.h
index 6e9d6dc82..64bac448a 100644
--- a/src/crypto/common.h
+++ b/src/crypto/common.h
@@ -9,9 +9,10 @@
 #include <config/bitcoin-config.h>
 #endif
 
+#include <assert.h>
 #include <stdint.h>
 #include <string.h>
-
+#include <sodium.h>
 #include <compat/endian.h>
 
 uint16_t static inline ReadLE16(const unsigned char* ptr)
@@ -100,4 +101,42 @@ uint64_t static inline CountBits(uint64_t x)
     return ret;
 }
 
+int inline init_and_check_sodium()
+{
+    if (sodium_init() == -1) {
+        return -1;
+    }
+
+    // What follows is a runtime test that ensures the version of libsodium
+    // we're linked against checks that signatures are canonical (s < L).
+    const unsigned char message[1] = { 0 };
+
+    unsigned char pk[crypto_sign_PUBLICKEYBYTES];
+    unsigned char sk[crypto_sign_SECRETKEYBYTES];
+    unsigned char sig[crypto_sign_BYTES];
+
+    crypto_sign_keypair(pk, sk);
+    crypto_sign_detached(sig, NULL, message, sizeof(message), sk);
+
+    assert(crypto_sign_verify_detached(sig, message, sizeof(message), pk) == 0);
+
+    // Copied from libsodium/crypto_sign/ed25519/ref10/open.c
+    static const unsigned char L[32] =
+        { 0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58,
+          0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14,
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10 };
+
+    // Add L to S, which starts at sig[32].
+    unsigned int s = 0;
+    for (size_t i = 0; i < 32; i++) {
+        s = sig[32 + i] + L[i] + (s >> 8);
+        sig[32 + i] = s & 0xff;
+    }
+
+    assert(crypto_sign_verify_detached(sig, message, sizeof(message), pk) != 0);
+
+    return 0;
+}
+
 #endif // BITCOIN_CRYPTO_COMMON_H
diff --git a/src/crypto/equihash.cpp b/src/crypto/equihash.cpp
new file mode 100644
index 000000000..358b231ea
--- /dev/null
+++ b/src/crypto/equihash.cpp
@@ -0,0 +1,816 @@
+// Copyright (c) 2016 Jack Grigg
+// Copyright (c) 2016 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+// Implementation of the Equihash Proof-of-Work algorithm.
+//
+// Reference
+// =========
+// Alex Biryukov and Dmitry Khovratovich
+// Equihash: Asymmetric Proof-of-Work Based on the Generalized Birthday Problem
+// NDSS ’16, 21-24 February 2016, San Diego, CA, USA
+// https://www.internetsociety.org/sites/default/files/blogs-media/equihash-asymmetric-proof-of-work-based-generalized-birthday-problem.pdf
+
+#if defined(HAVE_CONFIG_H)
+#include "config/bitcoin-config.h"
+#endif
+
+#include "compat/endian.h"
+#include "crypto/equihash.h"
+#include "util.h"
+
+#include <algorithm>
+#include <iostream>
+#include <stdexcept>
+
+#include <boost/optional.hpp>
+
+EhSolverCancelledException solver_cancelled;
+
+template<unsigned int N, unsigned int K>
+int Equihash<N,K>::InitialiseState(eh_HashState& base_state)
+{
+    uint32_t le_N = htole32(N);
+    uint32_t le_K = htole32(K);
+    unsigned char personalization[crypto_generichash_blake2b_PERSONALBYTES] = {};
+    memcpy(personalization, "ZcashPoW", 8);
+    memcpy(personalization+8,  &le_N, 4);
+    memcpy(personalization+12, &le_K, 4);
+    return crypto_generichash_blake2b_init_salt_personal(&base_state,
+                                                         NULL, 0, // No key.
+                                                         (512/N)*N/8,
+                                                         NULL,    // No salt.
+                                                         personalization);
+}
+
+void GenerateHash(const eh_HashState& base_state, eh_index g,
+                  unsigned char* hash, size_t hLen)
+{
+    eh_HashState state;
+    state = base_state;
+    eh_index lei = htole32(g);
+    crypto_generichash_blake2b_update(&state, (const unsigned char*) &lei,
+                                      sizeof(eh_index));
+    crypto_generichash_blake2b_final(&state, hash, hLen);
+}
+
+void ExpandArray(const unsigned char* in, size_t in_len,
+                 unsigned char* out, size_t out_len,
+                 size_t bit_len, size_t byte_pad)
+{
+    assert(bit_len >= 8);
+    assert(8*sizeof(uint32_t) >= 7+bit_len);
+
+    size_t out_width { (bit_len+7)/8 + byte_pad };
+    assert(out_len == 8*out_width*in_len/bit_len);
+
+    uint32_t bit_len_mask { ((uint32_t)1 << bit_len) - 1 };
+
+    // The acc_bits least-significant bits of acc_value represent a bit sequence
+    // in big-endian order.
+    size_t acc_bits = 0;
+    uint32_t acc_value = 0;
+
+    size_t j = 0;
+    for (size_t i = 0; i < in_len; i++) {
+        acc_value = (acc_value << 8) | in[i];
+        acc_bits += 8;
+
+        // When we have bit_len or more bits in the accumulator, write the next
+        // output element.
+        if (acc_bits >= bit_len) {
+            acc_bits -= bit_len;
+            for (size_t x = 0; x < byte_pad; x++) {
+                out[j+x] = 0;
+            }
+            for (size_t x = byte_pad; x < out_width; x++) {
+                out[j+x] = (
+                    // Big-endian
+                    acc_value >> (acc_bits+(8*(out_width-x-1)))
+                ) & (
+                    // Apply bit_len_mask across byte boundaries
+                    (bit_len_mask >> (8*(out_width-x-1))) & 0xFF
+                );
+            }
+            j += out_width;
+        }
+    }
+}
+
+void CompressArray(const unsigned char* in, size_t in_len,
+                   unsigned char* out, size_t out_len,
+                   size_t bit_len, size_t byte_pad)
+{
+    assert(bit_len >= 8);
+    assert(8*sizeof(uint32_t) >= 7+bit_len);
+
+    size_t in_width { (bit_len+7)/8 + byte_pad };
+    assert(out_len == bit_len*in_len/(8*in_width));
+
+    uint32_t bit_len_mask { ((uint32_t)1 << bit_len) - 1 };
+
+    // The acc_bits least-significant bits of acc_value represent a bit sequence
+    // in big-endian order.
+    size_t acc_bits = 0;
+    uint32_t acc_value = 0;
+
+    size_t j = 0;
+    for (size_t i = 0; i < out_len; i++) {
+        // When we have fewer than 8 bits left in the accumulator, read the next
+        // input element.
+        if (acc_bits < 8) {
+            acc_value = acc_value << bit_len;
+            for (size_t x = byte_pad; x < in_width; x++) {
+                acc_value = acc_value | (
+                    (
+                        // Apply bit_len_mask across byte boundaries
+                        in[j+x] & ((bit_len_mask >> (8*(in_width-x-1))) & 0xFF)
+                    ) << (8*(in_width-x-1))); // Big-endian
+            }
+            j += in_width;
+            acc_bits += bit_len;
+        }
+
+        acc_bits -= 8;
+        out[i] = (acc_value >> acc_bits) & 0xFF;
+    }
+}
+
+// Big-endian so that lexicographic array comparison is equivalent to integer
+// comparison
+void EhIndexToArray(const eh_index i, unsigned char* array)
+{
+    BOOST_STATIC_ASSERT(sizeof(eh_index) == 4);
+    eh_index bei = htobe32(i);
+    memcpy(array, &bei, sizeof(eh_index));
+}
+
+// Big-endian so that lexicographic array comparison is equivalent to integer
+// comparison
+eh_index ArrayToEhIndex(const unsigned char* array)
+{
+    BOOST_STATIC_ASSERT(sizeof(eh_index) == 4);
+    eh_index bei;
+    memcpy(&bei, array, sizeof(eh_index));
+    return be32toh(bei);
+}
+
+eh_trunc TruncateIndex(const eh_index i, const unsigned int ilen)
+{
+    // Truncate to 8 bits
+    BOOST_STATIC_ASSERT(sizeof(eh_trunc) == 1);
+    return (i >> (ilen - 8)) & 0xff;
+}
+
+eh_index UntruncateIndex(const eh_trunc t, const eh_index r, const unsigned int ilen)
+{
+    eh_index i{t};
+    return (i << (ilen - 8)) | r;
+}
+
+std::vector<eh_index> GetIndicesFromMinimal(std::vector<unsigned char> minimal,
+                                            size_t cBitLen)
+{
+    assert(((cBitLen+1)+7)/8 <= sizeof(eh_index));
+    size_t lenIndices { 8*sizeof(eh_index)*minimal.size()/(cBitLen+1) };
+    size_t bytePad { sizeof(eh_index) - ((cBitLen+1)+7)/8 };
+    std::vector<unsigned char> array(lenIndices);
+    ExpandArray(minimal.data(), minimal.size(),
+                array.data(), lenIndices, cBitLen+1, bytePad);
+    std::vector<eh_index> ret;
+    for (int i = 0; i < lenIndices; i += sizeof(eh_index)) {
+        ret.push_back(ArrayToEhIndex(array.data()+i));
+    }
+    return ret;
+}
+
+std::vector<unsigned char> GetMinimalFromIndices(std::vector<eh_index> indices,
+                                                 size_t cBitLen)
+{
+    assert(((cBitLen+1)+7)/8 <= sizeof(eh_index));
+    size_t lenIndices { indices.size()*sizeof(eh_index) };
+    size_t minLen { (cBitLen+1)*lenIndices/(8*sizeof(eh_index)) };
+    size_t bytePad { sizeof(eh_index) - ((cBitLen+1)+7)/8 };
+    std::vector<unsigned char> array(lenIndices);
+    for (int i = 0; i < indices.size(); i++) {
+        EhIndexToArray(indices[i], array.data()+(i*sizeof(eh_index)));
+    }
+    std::vector<unsigned char> ret(minLen);
+    CompressArray(array.data(), lenIndices,
+                  ret.data(), minLen, cBitLen+1, bytePad);
+    return ret;
+}
+
+template<size_t WIDTH>
+StepRow<WIDTH>::StepRow(const unsigned char* hashIn, size_t hInLen,
+                        size_t hLen, size_t cBitLen)
+{
+    assert(hLen <= WIDTH);
+    ExpandArray(hashIn, hInLen, hash, hLen, cBitLen);
+}
+
+template<size_t WIDTH> template<size_t W>
+StepRow<WIDTH>::StepRow(const StepRow<W>& a)
+{
+    BOOST_STATIC_ASSERT(W <= WIDTH);
+    std::copy(a.hash, a.hash+W, hash);
+}
+
+template<size_t WIDTH>
+FullStepRow<WIDTH>::FullStepRow(const unsigned char* hashIn, size_t hInLen,
+                                size_t hLen, size_t cBitLen, eh_index i) :
+        StepRow<WIDTH> {hashIn, hInLen, hLen, cBitLen}
+{
+    EhIndexToArray(i, hash+hLen);
+}
+
+template<size_t WIDTH> template<size_t W>
+FullStepRow<WIDTH>::FullStepRow(const FullStepRow<W>& a, const FullStepRow<W>& b, size_t len, size_t lenIndices, int trim) :
+        StepRow<WIDTH> {a}
+{
+    assert(len+lenIndices <= W);
+    assert(len-trim+(2*lenIndices) <= WIDTH);
+    for (int i = trim; i < len; i++)
+        hash[i-trim] = a.hash[i] ^ b.hash[i];
+    if (a.IndicesBefore(b, len, lenIndices)) {
+        std::copy(a.hash+len, a.hash+len+lenIndices, hash+len-trim);
+        std::copy(b.hash+len, b.hash+len+lenIndices, hash+len-trim+lenIndices);
+    } else {
+        std::copy(b.hash+len, b.hash+len+lenIndices, hash+len-trim);
+        std::copy(a.hash+len, a.hash+len+lenIndices, hash+len-trim+lenIndices);
+    }
+}
+
+template<size_t WIDTH>
+FullStepRow<WIDTH>& FullStepRow<WIDTH>::operator=(const FullStepRow<WIDTH>& a)
+{
+    std::copy(a.hash, a.hash+WIDTH, hash);
+    return *this;
+}
+
+template<size_t WIDTH>
+bool StepRow<WIDTH>::IsZero(size_t len)
+{
+    // This doesn't need to be constant time.
+    for (int i = 0; i < len; i++) {
+        if (hash[i] != 0)
+            return false;
+    }
+    return true;
+}
+
+template<size_t WIDTH>
+std::vector<unsigned char> FullStepRow<WIDTH>::GetIndices(size_t len, size_t lenIndices,
+                                                          size_t cBitLen) const
+{
+    assert(((cBitLen+1)+7)/8 <= sizeof(eh_index));
+    size_t minLen { (cBitLen+1)*lenIndices/(8*sizeof(eh_index)) };
+    size_t bytePad { sizeof(eh_index) - ((cBitLen+1)+7)/8 };
+    std::vector<unsigned char> ret(minLen);
+    CompressArray(hash+len, lenIndices, ret.data(), minLen, cBitLen+1, bytePad);
+    return ret;
+}
+
+template<size_t WIDTH>
+bool HasCollision(StepRow<WIDTH>& a, StepRow<WIDTH>& b, int l)
+{
+    // This doesn't need to be constant time.
+    for (int j = 0; j < l; j++) {
+        if (a.hash[j] != b.hash[j])
+            return false;
+    }
+    return true;
+}
+
+template<size_t WIDTH>
+TruncatedStepRow<WIDTH>::TruncatedStepRow(const unsigned char* hashIn, size_t hInLen,
+                                          size_t hLen, size_t cBitLen,
+                                          eh_index i, unsigned int ilen) :
+        StepRow<WIDTH> {hashIn, hInLen, hLen, cBitLen}
+{
+    hash[hLen] = TruncateIndex(i, ilen);
+}
+
+template<size_t WIDTH> template<size_t W>
+TruncatedStepRow<WIDTH>::TruncatedStepRow(const TruncatedStepRow<W>& a, const TruncatedStepRow<W>& b, size_t len, size_t lenIndices, int trim) :
+        StepRow<WIDTH> {a}
+{
+    assert(len+lenIndices <= W);
+    assert(len-trim+(2*lenIndices) <= WIDTH);
+    for (int i = trim; i < len; i++)
+        hash[i-trim] = a.hash[i] ^ b.hash[i];
+    if (a.IndicesBefore(b, len, lenIndices)) {
+        std::copy(a.hash+len, a.hash+len+lenIndices, hash+len-trim);
+        std::copy(b.hash+len, b.hash+len+lenIndices, hash+len-trim+lenIndices);
+    } else {
+        std::copy(b.hash+len, b.hash+len+lenIndices, hash+len-trim);
+        std::copy(a.hash+len, a.hash+len+lenIndices, hash+len-trim+lenIndices);
+    }
+}
+
+template<size_t WIDTH>
+TruncatedStepRow<WIDTH>& TruncatedStepRow<WIDTH>::operator=(const TruncatedStepRow<WIDTH>& a)
+{
+    std::copy(a.hash, a.hash+WIDTH, hash);
+    return *this;
+}
+
+template<size_t WIDTH>
+std::shared_ptr<eh_trunc> TruncatedStepRow<WIDTH>::GetTruncatedIndices(size_t len, size_t lenIndices) const
+{
+    std::shared_ptr<eh_trunc> p (new eh_trunc[lenIndices], std::default_delete<eh_trunc[]>());
+    std::copy(hash+len, hash+len+lenIndices, p.get());
+    return p;
+}
+
+#ifdef ENABLE_MINING
+template<unsigned int N, unsigned int K>
+bool Equihash<N,K>::BasicSolve(const eh_HashState& base_state,
+                               const std::function<bool(std::vector<unsigned char>)> validBlock,
+                               const std::function<bool(EhSolverCancelCheck)> cancelled)
+{
+    eh_index init_size { 1 << (CollisionBitLength + 1) };
+
+    // 1) Generate first list
+    LogPrint(BCLog::EQUIHASH, "Generating first list\n");
+    size_t hashLen = HashLength;
+    size_t lenIndices = sizeof(eh_index);
+    std::vector<FullStepRow<FullWidth>> X;
+    X.reserve(init_size);
+    unsigned char tmpHash[HashOutput];
+    for (eh_index g = 0; X.size() < init_size; g++) {
+        GenerateHash(base_state, g, tmpHash, HashOutput);
+        for (eh_index i = 0; i < IndicesPerHashOutput && X.size() < init_size; i++) {
+            X.emplace_back(tmpHash+(i*N/8), N/8, HashLength,
+                           CollisionBitLength, (g*IndicesPerHashOutput)+i);
+        }
+        if (cancelled(ListGeneration)) throw solver_cancelled;
+    }
+
+    // 3) Repeat step 2 until 2n/(k+1) bits remain
+    for (int r = 1; r < K && X.size() > 0; r++) {
+        LogPrint(BCLog::EQUIHASH, "Round %d:\n", r);
+        // 2a) Sort the list
+        LogPrint(BCLog::EQUIHASH, "- Sorting list\n");
+        std::sort(X.begin(), X.end(), CompareSR(CollisionByteLength));
+        if (cancelled(ListSorting)) throw solver_cancelled;
+
+        LogPrint(BCLog::EQUIHASH, "- Finding collisions\n");
+        int i = 0;
+        int posFree = 0;
+        std::vector<FullStepRow<FullWidth>> Xc;
+        while (i < X.size() - 1) {
+            // 2b) Find next set of unordered pairs with collisions on the next n/(k+1) bits
+            int j = 1;
+            while (i+j < X.size() &&
+                    HasCollision(X[i], X[i+j], CollisionByteLength)) {
+                j++;
+            }
+
+            // 2c) Calculate tuples (X_i ^ X_j, (i, j))
+            for (int l = 0; l < j - 1; l++) {
+                for (int m = l + 1; m < j; m++) {
+                    if (DistinctIndices(X[i+l], X[i+m], hashLen, lenIndices)) {
+                        Xc.emplace_back(X[i+l], X[i+m], hashLen, lenIndices, CollisionByteLength);
+                    }
+                }
+            }
+
+            // 2d) Store tuples on the table in-place if possible
+            while (posFree < i+j && Xc.size() > 0) {
+                X[posFree++] = Xc.back();
+                Xc.pop_back();
+            }
+
+            i += j;
+            if (cancelled(ListColliding)) throw solver_cancelled;
+        }
+
+        // 2e) Handle edge case where final table entry has no collision
+        while (posFree < X.size() && Xc.size() > 0) {
+            X[posFree++] = Xc.back();
+            Xc.pop_back();
+        }
+
+        if (Xc.size() > 0) {
+            // 2f) Add overflow to end of table
+            X.insert(X.end(), Xc.begin(), Xc.end());
+        } else if (posFree < X.size()) {
+            // 2g) Remove empty space at the end
+            X.erase(X.begin()+posFree, X.end());
+            X.shrink_to_fit();
+        }
+
+        hashLen -= CollisionByteLength;
+        lenIndices *= 2;
+        if (cancelled(RoundEnd)) throw solver_cancelled;
+    }
+
+    // k+1) Find a collision on last 2n(k+1) bits
+    LogPrint(BCLog::EQUIHASH, "Final round:\n");
+    if (X.size() > 1) {
+        LogPrint(BCLog::EQUIHASH, "- Sorting list\n");
+        std::sort(X.begin(), X.end(), CompareSR(hashLen));
+        if (cancelled(FinalSorting)) throw solver_cancelled;
+        LogPrint(BCLog::EQUIHASH, "- Finding collisions\n");
+        int i = 0;
+        while (i < X.size() - 1) {
+            int j = 1;
+            while (i+j < X.size() &&
+                    HasCollision(X[i], X[i+j], hashLen)) {
+                j++;
+            }
+
+            for (int l = 0; l < j - 1; l++) {
+                for (int m = l + 1; m < j; m++) {
+                    FullStepRow<FinalFullWidth> res(X[i+l], X[i+m], hashLen, lenIndices, 0);
+                    if (DistinctIndices(X[i+l], X[i+m], hashLen, lenIndices)) {
+                        auto soln = res.GetIndices(hashLen, 2*lenIndices, CollisionBitLength);
+                        assert(soln.size() == equihash_solution_size(N, K));
+                        if (validBlock(soln)) {
+                            return true;
+                        }
+                    }
+                }
+            }
+
+            i += j;
+            if (cancelled(FinalColliding)) throw solver_cancelled;
+        }
+    } else
+        LogPrint(BCLog::EQUIHASH, "- List is empty\n");
+
+    return false;
+}
+
+template<size_t WIDTH>
+void CollideBranches(std::vector<FullStepRow<WIDTH>>& X, const size_t hlen, const size_t lenIndices, const unsigned int clen, const unsigned int ilen, const eh_trunc lt, const eh_trunc rt)
+{
+    int i = 0;
+    int posFree = 0;
+    std::vector<FullStepRow<WIDTH>> Xc;
+    while (i < X.size() - 1) {
+        // 2b) Find next set of unordered pairs with collisions on the next n/(k+1) bits
+        int j = 1;
+        while (i+j < X.size() &&
+                HasCollision(X[i], X[i+j], clen)) {
+            j++;
+        }
+
+        // 2c) Calculate tuples (X_i ^ X_j, (i, j))
+        for (int l = 0; l < j - 1; l++) {
+            for (int m = l + 1; m < j; m++) {
+                if (DistinctIndices(X[i+l], X[i+m], hlen, lenIndices)) {
+                    if (IsValidBranch(X[i+l], hlen, ilen, lt) && IsValidBranch(X[i+m], hlen, ilen, rt)) {
+                        Xc.emplace_back(X[i+l], X[i+m], hlen, lenIndices, clen);
+                    } else if (IsValidBranch(X[i+m], hlen, ilen, lt) && IsValidBranch(X[i+l], hlen, ilen, rt)) {
+                        Xc.emplace_back(X[i+m], X[i+l], hlen, lenIndices, clen);
+                    }
+                }
+            }
+        }
+
+        // 2d) Store tuples on the table in-place if possible
+        while (posFree < i+j && Xc.size() > 0) {
+            X[posFree++] = Xc.back();
+            Xc.pop_back();
+        }
+
+        i += j;
+    }
+
+    // 2e) Handle edge case where final table entry has no collision
+    while (posFree < X.size() && Xc.size() > 0) {
+        X[posFree++] = Xc.back();
+        Xc.pop_back();
+    }
+
+    if (Xc.size() > 0) {
+        // 2f) Add overflow to end of table
+        X.insert(X.end(), Xc.begin(), Xc.end());
+    } else if (posFree < X.size()) {
+        // 2g) Remove empty space at the end
+        X.erase(X.begin()+posFree, X.end());
+        X.shrink_to_fit();
+    }
+}
+
+template<unsigned int N, unsigned int K>
+bool Equihash<N,K>::OptimisedSolve(const eh_HashState& base_state,
+                                   const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                   const std::function<bool(EhSolverCancelCheck)> cancelled)
+{
+    eh_index init_size { 1 << (CollisionBitLength + 1) };
+    eh_index recreate_size { UntruncateIndex(1, 0, CollisionBitLength + 1) };
+
+    // First run the algorithm with truncated indices
+
+    const eh_index soln_size { 1 << K };
+    std::vector<std::shared_ptr<eh_trunc>> partialSolns;
+    int invalidCount = 0;
+    {
+
+        // 1) Generate first list
+        LogPrint(BCLog::EQUIHASH, "Generating first list\n");
+        size_t hashLen = HashLength;
+        size_t lenIndices = sizeof(eh_trunc);
+        std::vector<TruncatedStepRow<TruncatedWidth>> Xt;
+        Xt.reserve(init_size);
+        unsigned char tmpHash[HashOutput];
+        for (eh_index g = 0; Xt.size() < init_size; g++) {
+            GenerateHash(base_state, g, tmpHash, HashOutput);
+            for (eh_index i = 0; i < IndicesPerHashOutput && Xt.size() < init_size; i++) {
+                Xt.emplace_back(tmpHash+(i*N/8), N/8, HashLength, CollisionBitLength,
+                                (g*IndicesPerHashOutput)+i, CollisionBitLength + 1);
+            }
+            if (cancelled(ListGeneration)) throw solver_cancelled;
+        }
+
+        // 3) Repeat step 2 until 2n/(k+1) bits remain
+        for (int r = 1; r < K && Xt.size() > 0; r++) {
+            LogPrint(BCLog::EQUIHASH, "Round %d:\n", r);
+            // 2a) Sort the list
+            LogPrint(BCLog::EQUIHASH, "- Sorting list\n");
+            std::sort(Xt.begin(), Xt.end(), CompareSR(CollisionByteLength));
+            if (cancelled(ListSorting)) throw solver_cancelled;
+
+            LogPrint(BCLog::EQUIHASH, "- Finding collisions\n");
+            int i = 0;
+            int posFree = 0;
+            std::vector<TruncatedStepRow<TruncatedWidth>> Xc;
+            while (i < Xt.size() - 1) {
+                // 2b) Find next set of unordered pairs with collisions on the next n/(k+1) bits
+                int j = 1;
+                while (i+j < Xt.size() &&
+                        HasCollision(Xt[i], Xt[i+j], CollisionByteLength)) {
+                    j++;
+                }
+
+                // 2c) Calculate tuples (X_i ^ X_j, (i, j))
+                bool checking_for_zero = (i == 0 && Xt[0].IsZero(hashLen));
+                for (int l = 0; l < j - 1; l++) {
+                    for (int m = l + 1; m < j; m++) {
+                        // We truncated, so don't check for distinct indices here
+                        TruncatedStepRow<TruncatedWidth> Xi {Xt[i+l], Xt[i+m],
+                                                             hashLen, lenIndices,
+                                                             CollisionByteLength};
+                        if (!(Xi.IsZero(hashLen-CollisionByteLength) &&
+                              IsProbablyDuplicate<soln_size>(Xi.GetTruncatedIndices(hashLen-CollisionByteLength, 2*lenIndices),
+                                                             2*lenIndices))) {
+                            Xc.emplace_back(Xi);
+                        }
+                    }
+                }
+
+                // 2d) Store tuples on the table in-place if possible
+                while (posFree < i+j && Xc.size() > 0) {
+                    Xt[posFree++] = Xc.back();
+                    Xc.pop_back();
+                }
+
+                i += j;
+                if (cancelled(ListColliding)) throw solver_cancelled;
+            }
+
+            // 2e) Handle edge case where final table entry has no collision
+            while (posFree < Xt.size() && Xc.size() > 0) {
+                Xt[posFree++] = Xc.back();
+                Xc.pop_back();
+            }
+
+            if (Xc.size() > 0) {
+                // 2f) Add overflow to end of table
+                Xt.insert(Xt.end(), Xc.begin(), Xc.end());
+            } else if (posFree < Xt.size()) {
+                // 2g) Remove empty space at the end
+                Xt.erase(Xt.begin()+posFree, Xt.end());
+                Xt.shrink_to_fit();
+            }
+
+            hashLen -= CollisionByteLength;
+            lenIndices *= 2;
+            if (cancelled(RoundEnd)) throw solver_cancelled;
+        }
+
+        // k+1) Find a collision on last 2n(k+1) bits
+        LogPrint(BCLog::EQUIHASH, "Final round:\n");
+        if (Xt.size() > 1) {
+            LogPrint(BCLog::EQUIHASH, "- Sorting list\n");
+            std::sort(Xt.begin(), Xt.end(), CompareSR(hashLen));
+            if (cancelled(FinalSorting)) throw solver_cancelled;
+            LogPrint(BCLog::EQUIHASH, "- Finding collisions\n");
+            int i = 0;
+            while (i < Xt.size() - 1) {
+                int j = 1;
+                while (i+j < Xt.size() &&
+                        HasCollision(Xt[i], Xt[i+j], hashLen)) {
+                    j++;
+                }
+
+                for (int l = 0; l < j - 1; l++) {
+                    for (int m = l + 1; m < j; m++) {
+                        TruncatedStepRow<FinalTruncatedWidth> res(Xt[i+l], Xt[i+m],
+                                                                  hashLen, lenIndices, 0);
+                        auto soln = res.GetTruncatedIndices(hashLen, 2*lenIndices);
+                        if (!IsProbablyDuplicate<soln_size>(soln, 2*lenIndices)) {
+                            partialSolns.push_back(soln);
+                        }
+                    }
+                }
+
+                i += j;
+                if (cancelled(FinalColliding)) throw solver_cancelled;
+            }
+        } else
+            LogPrint(BCLog::EQUIHASH, "- List is empty\n");
+
+    } // Ensure Xt goes out of scope and is destroyed
+
+    LogPrint(BCLog::EQUIHASH, "Found %d partial solutions\n", partialSolns.size());
+
+    // Now for each solution run the algorithm again to recreate the indices
+    LogPrint(BCLog::EQUIHASH, "Culling solutions\n");
+    for (std::shared_ptr<eh_trunc> partialSoln : partialSolns) {
+        std::set<std::vector<unsigned char>> solns;
+        size_t hashLen;
+        size_t lenIndices;
+        unsigned char tmpHash[HashOutput];
+        std::vector<boost::optional<std::vector<FullStepRow<FinalFullWidth>>>> X;
+        X.reserve(K+1);
+
+        // 3) Repeat steps 1 and 2 for each partial index
+        for (eh_index i = 0; i < soln_size; i++) {
+            // 1) Generate first list of possibilities
+            std::vector<FullStepRow<FinalFullWidth>> icv;
+            icv.reserve(recreate_size);
+            for (eh_index j = 0; j < recreate_size; j++) {
+                eh_index newIndex { UntruncateIndex(partialSoln.get()[i], j, CollisionBitLength + 1) };
+                if (j == 0 || newIndex % IndicesPerHashOutput == 0) {
+                    GenerateHash(base_state, newIndex/IndicesPerHashOutput,
+                                 tmpHash, HashOutput);
+                }
+                icv.emplace_back(tmpHash+((newIndex % IndicesPerHashOutput) * N/8),
+                                 N/8, HashLength, CollisionBitLength, newIndex);
+                if (cancelled(PartialGeneration)) throw solver_cancelled;
+            }
+            boost::optional<std::vector<FullStepRow<FinalFullWidth>>> ic = icv;
+
+            // 2a) For each pair of lists:
+            hashLen = HashLength;
+            lenIndices = sizeof(eh_index);
+            size_t rti = i;
+            for (size_t r = 0; r <= K; r++) {
+                // 2b) Until we are at the top of a subtree:
+                if (r < X.size()) {
+                    if (X[r]) {
+                        // 2c) Merge the lists
+                        ic->reserve(ic->size() + X[r]->size());
+                        ic->insert(ic->end(), X[r]->begin(), X[r]->end());
+                        std::sort(ic->begin(), ic->end(), CompareSR(hashLen));
+                        if (cancelled(PartialSorting)) throw solver_cancelled;
+                        size_t lti = rti-(1<<r);
+                        CollideBranches(*ic, hashLen, lenIndices,
+                                        CollisionByteLength,
+                                        CollisionBitLength + 1,
+                                        partialSoln.get()[lti], partialSoln.get()[rti]);
+
+                        // 2d) Check if this has become an invalid solution
+                        if (ic->size() == 0)
+                            goto invalidsolution;
+
+                        X[r] = boost::none;
+                        hashLen -= CollisionByteLength;
+                        lenIndices *= 2;
+                        rti = lti;
+                    } else {
+                        X[r] = *ic;
+                        break;
+                    }
+                } else {
+                    X.push_back(ic);
+                    break;
+                }
+                if (cancelled(PartialSubtreeEnd)) throw solver_cancelled;
+            }
+            if (cancelled(PartialIndexEnd)) throw solver_cancelled;
+        }
+
+        // We are at the top of the tree
+        assert(X.size() == K+1);
+        for (FullStepRow<FinalFullWidth> row : *X[K]) {
+            auto soln = row.GetIndices(hashLen, lenIndices, CollisionBitLength);
+            assert(soln.size() == equihash_solution_size(N, K));
+            solns.insert(soln);
+        }
+        for (auto soln : solns) {
+            if (validBlock(soln))
+                return true;
+        }
+        if (cancelled(PartialEnd)) throw solver_cancelled;
+        continue;
+
+invalidsolution:
+        invalidCount++;
+    }
+    LogPrint(BCLog::EQUIHASH, "- Number of invalid solutions found: %d\n", invalidCount);
+
+    return false;
+}
+#endif // ENABLE_MINING
+
+template<unsigned int N, unsigned int K>
+bool Equihash<N,K>::IsValidSolution(const eh_HashState& base_state, std::vector<unsigned char> soln)
+{
+    if (soln.size() != SolutionWidth) {
+        LogPrint(BCLog::EQUIHASH, "Invalid solution length: %d (expected %d)\n",
+                 soln.size(), SolutionWidth);
+        return false;
+    }
+
+    std::vector<FullStepRow<FinalFullWidth>> X;
+    X.reserve(1 << K);
+    unsigned char tmpHash[HashOutput];
+    for (eh_index i : GetIndicesFromMinimal(soln, CollisionBitLength)) {
+        GenerateHash(base_state, i/IndicesPerHashOutput, tmpHash, HashOutput);
+        X.emplace_back(tmpHash+((i % IndicesPerHashOutput) * N/8),
+                       N/8, HashLength, CollisionBitLength, i);
+    }
+
+    size_t hashLen = HashLength;
+    size_t lenIndices = sizeof(eh_index);
+    while (X.size() > 1) {
+        std::vector<FullStepRow<FinalFullWidth>> Xc;
+        for (int i = 0; i < X.size(); i += 2) {
+            if (!HasCollision(X[i], X[i+1], CollisionByteLength)) {
+                LogPrint(BCLog::EQUIHASH, "Invalid solution: invalid collision length between StepRows\n");
+                LogPrint(BCLog::EQUIHASH, "X[i]   = %s\n", X[i].GetHex(hashLen));
+                LogPrint(BCLog::EQUIHASH, "X[i+1] = %s\n", X[i+1].GetHex(hashLen));
+                return false;
+            }
+            if (X[i+1].IndicesBefore(X[i], hashLen, lenIndices)) {
+                LogPrint(BCLog::EQUIHASH, "Invalid solution: Index tree incorrectly ordered\n");
+                return false;
+            }
+            if (!DistinctIndices(X[i], X[i+1], hashLen, lenIndices)) {
+                LogPrint(BCLog::EQUIHASH, "Invalid solution: duplicate indices\n");
+                return false;
+            }
+            Xc.emplace_back(X[i], X[i+1], hashLen, lenIndices, CollisionByteLength);
+        }
+        X = Xc;
+        hashLen -= CollisionByteLength;
+        lenIndices *= 2;
+    }
+
+    assert(X.size() == 1);
+    return X[0].IsZero(hashLen);
+}
+
+// Explicit instantiations for Equihash<96,3>
+template int Equihash<96,3>::InitialiseState(eh_HashState& base_state);
+#ifdef ENABLE_MINING
+template bool Equihash<96,3>::BasicSolve(const eh_HashState& base_state,
+                                         const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                         const std::function<bool(EhSolverCancelCheck)> cancelled);
+template bool Equihash<96,3>::OptimisedSolve(const eh_HashState& base_state,
+                                             const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                             const std::function<bool(EhSolverCancelCheck)> cancelled);
+#endif
+template bool Equihash<96,3>::IsValidSolution(const eh_HashState& base_state, std::vector<unsigned char> soln);
+
+// Explicit instantiations for Equihash<200,9>
+template int Equihash<200,9>::InitialiseState(eh_HashState& base_state);
+#ifdef ENABLE_MINING
+template bool Equihash<200,9>::BasicSolve(const eh_HashState& base_state,
+                                          const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                          const std::function<bool(EhSolverCancelCheck)> cancelled);
+template bool Equihash<200,9>::OptimisedSolve(const eh_HashState& base_state,
+                                              const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                              const std::function<bool(EhSolverCancelCheck)> cancelled);
+#endif
+template bool Equihash<200,9>::IsValidSolution(const eh_HashState& base_state, std::vector<unsigned char> soln);
+
+// Explicit instantiations for Equihash<96,5>
+template int Equihash<96,5>::InitialiseState(eh_HashState& base_state);
+#ifdef ENABLE_MINING
+template bool Equihash<96,5>::BasicSolve(const eh_HashState& base_state,
+                                         const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                         const std::function<bool(EhSolverCancelCheck)> cancelled);
+template bool Equihash<96,5>::OptimisedSolve(const eh_HashState& base_state,
+                                             const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                             const std::function<bool(EhSolverCancelCheck)> cancelled);
+#endif
+template bool Equihash<96,5>::IsValidSolution(const eh_HashState& base_state, std::vector<unsigned char> soln);
+
+// Explicit instantiations for Equihash<48,5>
+template int Equihash<48,5>::InitialiseState(eh_HashState& base_state);
+#ifdef ENABLE_MINING
+template bool Equihash<48,5>::BasicSolve(const eh_HashState& base_state,
+                                         const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                         const std::function<bool(EhSolverCancelCheck)> cancelled);
+template bool Equihash<48,5>::OptimisedSolve(const eh_HashState& base_state,
+                                             const std::function<bool(std::vector<unsigned char>)> validBlock,
+                                             const std::function<bool(EhSolverCancelCheck)> cancelled);
+#endif
+template bool Equihash<48,5>::IsValidSolution(const eh_HashState& base_state, std::vector<unsigned char> soln);
diff --git a/src/crypto/equihash.h b/src/crypto/equihash.h
new file mode 100644
index 000000000..6691844ba
--- /dev/null
+++ b/src/crypto/equihash.h
@@ -0,0 +1,279 @@
+// Copyright (c) 2016 Jack Grigg
+// Copyright (c) 2016 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_EQUIHASH_H
+#define BITCOIN_EQUIHASH_H
+
+#include "crypto/sha256.h"
+#include "utilstrencodings.h"
+
+#include "sodium.h"
+
+#include <cstring>
+#include <exception>
+#include <functional>
+#include <memory>
+#include <set>
+#include <vector>
+
+#include <boost/static_assert.hpp>
+
+typedef crypto_generichash_blake2b_state eh_HashState;
+typedef uint32_t eh_index;
+typedef uint8_t eh_trunc;
+
+void ExpandArray(const unsigned char* in, size_t in_len,
+                 unsigned char* out, size_t out_len,
+                 size_t bit_len, size_t byte_pad=0);
+void CompressArray(const unsigned char* in, size_t in_len,
+                   unsigned char* out, size_t out_len,
+                   size_t bit_len, size_t byte_pad=0);
+
+eh_index ArrayToEhIndex(const unsigned char* array);
+eh_trunc TruncateIndex(const eh_index i, const unsigned int ilen);
+
+std::vector<eh_index> GetIndicesFromMinimal(std::vector<unsigned char> minimal,
+                                            size_t cBitLen);
+std::vector<unsigned char> GetMinimalFromIndices(std::vector<eh_index> indices,
+                                                 size_t cBitLen);
+
+template<size_t WIDTH>
+class StepRow
+{
+    template<size_t W>
+    friend class StepRow;
+    friend class CompareSR;
+
+protected:
+    unsigned char hash[WIDTH];
+
+public:
+    StepRow(const unsigned char* hashIn, size_t hInLen,
+            size_t hLen, size_t cBitLen);
+    ~StepRow() { }
+
+    template<size_t W>
+    StepRow(const StepRow<W>& a);
+
+    bool IsZero(size_t len);
+    std::string GetHex(size_t len) { return HexStr(hash, hash+len); }
+
+    template<size_t W>
+    friend bool HasCollision(StepRow<W>& a, StepRow<W>& b, int l);
+};
+
+class CompareSR
+{
+private:
+    size_t len;
+
+public:
+    CompareSR(size_t l) : len {l} { }
+
+    template<size_t W>
+    inline bool operator()(const StepRow<W>& a, const StepRow<W>& b) { return memcmp(a.hash, b.hash, len) < 0; }
+};
+
+template<size_t WIDTH>
+bool HasCollision(StepRow<WIDTH>& a, StepRow<WIDTH>& b, int l);
+
+template<size_t WIDTH>
+class FullStepRow : public StepRow<WIDTH>
+{
+    template<size_t W>
+    friend class FullStepRow;
+
+    using StepRow<WIDTH>::hash;
+
+public:
+    FullStepRow(const unsigned char* hashIn, size_t hInLen,
+                size_t hLen, size_t cBitLen, eh_index i);
+    ~FullStepRow() { }
+
+    FullStepRow(const FullStepRow<WIDTH>& a) : StepRow<WIDTH> {a} { }
+    template<size_t W>
+    FullStepRow(const FullStepRow<W>& a, const FullStepRow<W>& b, size_t len, size_t lenIndices, int trim);
+    FullStepRow& operator=(const FullStepRow<WIDTH>& a);
+
+    inline bool IndicesBefore(const FullStepRow<WIDTH>& a, size_t len, size_t lenIndices) const { return memcmp(hash+len, a.hash+len, lenIndices) < 0; }
+    std::vector<unsigned char> GetIndices(size_t len, size_t lenIndices,
+                                          size_t cBitLen) const;
+
+    template<size_t W>
+    friend bool DistinctIndices(const FullStepRow<W>& a, const FullStepRow<W>& b,
+                                size_t len, size_t lenIndices);
+    template<size_t W>
+    friend bool IsValidBranch(const FullStepRow<W>& a, const size_t len, const unsigned int ilen, const eh_trunc t);
+};
+
+template<size_t WIDTH>
+class TruncatedStepRow : public StepRow<WIDTH>
+{
+    template<size_t W>
+    friend class TruncatedStepRow;
+
+    using StepRow<WIDTH>::hash;
+
+public:
+    TruncatedStepRow(const unsigned char* hashIn, size_t hInLen,
+                     size_t hLen, size_t cBitLen,
+                     eh_index i, unsigned int ilen);
+    ~TruncatedStepRow() { }
+
+    TruncatedStepRow(const TruncatedStepRow<WIDTH>& a) : StepRow<WIDTH> {a} { }
+    template<size_t W>
+    TruncatedStepRow(const TruncatedStepRow<W>& a, const TruncatedStepRow<W>& b, size_t len, size_t lenIndices, int trim);
+    TruncatedStepRow& operator=(const TruncatedStepRow<WIDTH>& a);
+
+    inline bool IndicesBefore(const TruncatedStepRow<WIDTH>& a, size_t len, size_t lenIndices) const { return memcmp(hash+len, a.hash+len, lenIndices) < 0; }
+    std::shared_ptr<eh_trunc> GetTruncatedIndices(size_t len, size_t lenIndices) const;
+};
+
+enum EhSolverCancelCheck
+{
+    ListGeneration,
+    ListSorting,
+    ListColliding,
+    RoundEnd,
+    FinalSorting,
+    FinalColliding,
+    PartialGeneration,
+    PartialSorting,
+    PartialSubtreeEnd,
+    PartialIndexEnd,
+    PartialEnd
+};
+
+class EhSolverCancelledException : public std::exception
+{
+    virtual const char* what() const throw() {
+        return "Equihash solver was cancelled";
+    }
+};
+
+inline constexpr const size_t max(const size_t A, const size_t B) { return A > B ? A : B; }
+
+inline constexpr size_t equihash_solution_size(unsigned int N, unsigned int K) {
+    return (1 << K)*(N/(K+1)+1)/8;
+}
+
+template<unsigned int N, unsigned int K>
+class Equihash
+{
+private:
+    BOOST_STATIC_ASSERT(K < N);
+    BOOST_STATIC_ASSERT(N % 8 == 0);
+    BOOST_STATIC_ASSERT((N/(K+1)) + 1 < 8*sizeof(eh_index));
+
+public:
+    enum : size_t { IndicesPerHashOutput=512/N };
+    enum : size_t { HashOutput=IndicesPerHashOutput*N/8 };
+    enum : size_t { CollisionBitLength=N/(K+1) };
+    enum : size_t { CollisionByteLength=(CollisionBitLength+7)/8 };
+    enum : size_t { HashLength=(K+1)*CollisionByteLength };
+    enum : size_t { FullWidth=2*CollisionByteLength+sizeof(eh_index)*(1 << (K-1)) };
+    enum : size_t { FinalFullWidth=2*CollisionByteLength+sizeof(eh_index)*(1 << (K)) };
+    enum : size_t { TruncatedWidth=max(HashLength+sizeof(eh_trunc), 2*CollisionByteLength+sizeof(eh_trunc)*(1 << (K-1))) };
+    enum : size_t { FinalTruncatedWidth=max(HashLength+sizeof(eh_trunc), 2*CollisionByteLength+sizeof(eh_trunc)*(1 << (K))) };
+    enum : size_t { SolutionWidth=(1 << K)*(CollisionBitLength+1)/8 };
+
+    Equihash() { }
+
+    int InitialiseState(eh_HashState& base_state);
+#ifdef ENABLE_MINING
+    bool BasicSolve(const eh_HashState& base_state,
+                    const std::function<bool(std::vector<unsigned char>)> validBlock,
+                    const std::function<bool(EhSolverCancelCheck)> cancelled);
+    bool OptimisedSolve(const eh_HashState& base_state,
+                        const std::function<bool(std::vector<unsigned char>)> validBlock,
+                        const std::function<bool(EhSolverCancelCheck)> cancelled);
+#endif
+    bool IsValidSolution(const eh_HashState& base_state, std::vector<unsigned char> soln);
+};
+
+#include "equihash.tcc"
+
+static Equihash<96,3> Eh96_3;
+static Equihash<200,9> Eh200_9;
+static Equihash<96,5> Eh96_5;
+static Equihash<48,5> Eh48_5;
+
+#define EhInitialiseState(n, k, base_state)  \
+    if (n == 96 && k == 3) {                 \
+        Eh96_3.InitialiseState(base_state);  \
+    } else if (n == 200 && k == 9) {         \
+        Eh200_9.InitialiseState(base_state); \
+    } else if (n == 96 && k == 5) {          \
+        Eh96_5.InitialiseState(base_state);  \
+    } else if (n == 48 && k == 5) {          \
+        Eh48_5.InitialiseState(base_state);  \
+    } else {                                 \
+        throw std::invalid_argument("Unsupported Equihash parameters"); \
+    }
+
+#ifdef ENABLE_MINING
+inline bool EhBasicSolve(unsigned int n, unsigned int k, const eh_HashState& base_state,
+                    const std::function<bool(std::vector<unsigned char>)> validBlock,
+                    const std::function<bool(EhSolverCancelCheck)> cancelled)
+{
+    if (n == 96 && k == 3) {
+        return Eh96_3.BasicSolve(base_state, validBlock, cancelled);
+    } else if (n == 200 && k == 9) {
+        return Eh200_9.BasicSolve(base_state, validBlock, cancelled);
+    } else if (n == 96 && k == 5) {
+        return Eh96_5.BasicSolve(base_state, validBlock, cancelled);
+    } else if (n == 48 && k == 5) {
+        return Eh48_5.BasicSolve(base_state, validBlock, cancelled);
+    } else {
+        throw std::invalid_argument("Unsupported Equihash parameters");
+    }
+}
+
+inline bool EhBasicSolveUncancellable(unsigned int n, unsigned int k, const eh_HashState& base_state,
+                    const std::function<bool(std::vector<unsigned char>)> validBlock)
+{
+    return EhBasicSolve(n, k, base_state, validBlock,
+                        [](EhSolverCancelCheck pos) { return false; });
+}
+
+inline bool EhOptimisedSolve(unsigned int n, unsigned int k, const eh_HashState& base_state,
+                    const std::function<bool(std::vector<unsigned char>)> validBlock,
+                    const std::function<bool(EhSolverCancelCheck)> cancelled)
+{
+    if (n == 96 && k == 3) {
+        return Eh96_3.OptimisedSolve(base_state, validBlock, cancelled);
+    } else if (n == 200 && k == 9) {
+        return Eh200_9.OptimisedSolve(base_state, validBlock, cancelled);
+    } else if (n == 96 && k == 5) {
+        return Eh96_5.OptimisedSolve(base_state, validBlock, cancelled);
+    } else if (n == 48 && k == 5) {
+        return Eh48_5.OptimisedSolve(base_state, validBlock, cancelled);
+    } else {
+        throw std::invalid_argument("Unsupported Equihash parameters");
+    }
+}
+
+inline bool EhOptimisedSolveUncancellable(unsigned int n, unsigned int k, const eh_HashState& base_state,
+                    const std::function<bool(std::vector<unsigned char>)> validBlock)
+{
+    return EhOptimisedSolve(n, k, base_state, validBlock,
+                            [](EhSolverCancelCheck pos) { return false; });
+}
+#endif // ENABLE_MINING
+
+#define EhIsValidSolution(n, k, base_state, soln, ret)   \
+    if (n == 96 && k == 3) {                             \
+        ret = Eh96_3.IsValidSolution(base_state, soln);  \
+    } else if (n == 200 && k == 9) {                     \
+        ret = Eh200_9.IsValidSolution(base_state, soln); \
+    } else if (n == 96 && k == 5) {                      \
+        ret = Eh96_5.IsValidSolution(base_state, soln);  \
+    } else if (n == 48 && k == 5) {                      \
+        ret = Eh48_5.IsValidSolution(base_state, soln);  \
+    } else {                                             \
+        throw std::invalid_argument("Unsupported Equihash parameters"); \
+    }
+
+#endif // BITCOIN_EQUIHASH_H
diff --git a/src/crypto/equihash.tcc b/src/crypto/equihash.tcc
new file mode 100644
index 000000000..625749e47
--- /dev/null
+++ b/src/crypto/equihash.tcc
@@ -0,0 +1,49 @@
+// Copyright (c) 2016 Jack Grigg
+// Copyright (c) 2016 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <algorithm>
+#include <cassert>
+
+// Checks if the intersection of a.indices and b.indices is empty
+template<size_t WIDTH>
+bool DistinctIndices(const FullStepRow<WIDTH>& a, const FullStepRow<WIDTH>& b, size_t len, size_t lenIndices)
+{
+    for(size_t i = 0; i < lenIndices; i += sizeof(eh_index)) {
+        for(size_t j = 0; j < lenIndices; j += sizeof(eh_index)) {
+            if (memcmp(a.hash+len+i, b.hash+len+j, sizeof(eh_index)) == 0) {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+template<size_t MAX_INDICES>
+bool IsProbablyDuplicate(std::shared_ptr<eh_trunc> indices, size_t lenIndices)
+{
+    assert(lenIndices <= MAX_INDICES);
+    bool checked_index[MAX_INDICES] = {false};
+    int count_checked = 0;
+    for (int z = 0; z < lenIndices; z++) {
+        // Skip over indices we have already paired
+        if (!checked_index[z]) {
+            for (int y = z+1; y < lenIndices; y++) {
+                if (!checked_index[y] && indices.get()[z] == indices.get()[y]) {
+                    // Pair found
+                    checked_index[y] = true;
+                    count_checked += 2;
+                    break;
+                }
+            }
+        }
+    }
+    return count_checked == lenIndices;
+}
+
+template<size_t WIDTH>
+bool IsValidBranch(const FullStepRow<WIDTH>& a, const size_t len, const unsigned int ilen, const eh_trunc t)
+{
+    return TruncateIndex(ArrayToEhIndex(a.hash+len), ilen) == t;
+}
diff --git a/src/crypto/sha256.cpp b/src/crypto/sha256.cpp
index f3245b8de..cd2a9d0fb 100644
--- a/src/crypto/sha256.cpp
+++ b/src/crypto/sha256.cpp
@@ -8,6 +8,7 @@
 #include <assert.h>
 #include <string.h>
 #include <atomic>
+#include <stdexcept>
 
 #if defined(__x86_64__) || defined(__amd64__)
 #if defined(USE_ASM)
@@ -149,8 +150,8 @@ bool SelfTest(TransformType tr) {
     static const unsigned char in1[65] = {0, 0x80};
     static const unsigned char in2[129] = {
         0,
-        32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 
-        32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 
+        32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
+        32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0
     };
@@ -241,6 +242,22 @@ void CSHA256::Finalize(unsigned char hash[OUTPUT_SIZE])
     WriteBE32(hash + 28, s[7]);
 }
 
+void CSHA256::FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE], bool enforce_compression)
+{
+    if (enforce_compression && bytes != 64) {
+        throw std::length_error("SHA256Compress should be invoked with a 512-bit block");
+    }
+
+    WriteBE32(hash, s[0]);
+    WriteBE32(hash + 4, s[1]);
+    WriteBE32(hash + 8, s[2]);
+    WriteBE32(hash + 12, s[3]);
+    WriteBE32(hash + 16, s[4]);
+    WriteBE32(hash + 20, s[5]);
+    WriteBE32(hash + 24, s[6]);
+    WriteBE32(hash + 28, s[7]);
+}
+
 CSHA256& CSHA256::Reset()
 {
     bytes = 0;
diff --git a/src/crypto/sha256.h b/src/crypto/sha256.h
index dd30fe396..fbf14ab6a 100644
--- a/src/crypto/sha256.h
+++ b/src/crypto/sha256.h
@@ -23,6 +23,7 @@ public:
     CSHA256();
     CSHA256& Write(const unsigned char* data, size_t len);
     void Finalize(unsigned char hash[OUTPUT_SIZE]);
+    void FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE], bool enforce_compression = true);
     CSHA256& Reset();
 };
 
diff --git a/src/miner.cpp b/src/miner.cpp
index d4527a1d6..d7db49440 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -166,7 +166,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
     UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
     pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());
-    pblock->nNonce         = 0;
+    pblock->nNonce         = uint256();
     pblocktemplate->vTxSigOpsCost[0] = WITNESS_SCALE_FACTOR * GetLegacySigOpCount(*pblock->vtx[0]);
 
     CValidationState state;
diff --git a/src/paymentdisclosuredb.cpp b/src/paymentdisclosuredb.cpp
index ef32f2845..ccccf309f 100644
--- a/src/paymentdisclosuredb.cpp
+++ b/src/paymentdisclosuredb.cpp
@@ -2,10 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "paymentdisclosuredb.h"
+#include <paymentdisclosuredb.h>
 
-#include "util.h"
-#include "leveldbwrapper.h"
+#include <util.h>
+#include <dbwrapper.h>
 
 #include <boost/filesystem.hpp>
 
@@ -35,10 +35,10 @@ PaymentDisclosureDB::PaymentDisclosureDB(const boost::filesystem::path& dbPath)
         LogPrintf("PaymentDisclosure: using custom path for database: %s\n", path.string());
     }
 
-    TryCreateDirectory(path);
+    TryCreateDirectories(path);
     options.create_if_missing = true;
     leveldb::Status status = leveldb::DB::Open(options, path.string(), &db);
-    HandleError(status); // throws exception
+    dbwrapper_private::HandleError(status); // throws exception
     LogPrintf("PaymentDisclosure: Opened LevelDB successfully\n");
 }
 
@@ -57,12 +57,12 @@ bool PaymentDisclosureDB::Put(const PaymentDisclosureKey& key, const PaymentDisc
     std::lock_guard<std::mutex> guard(lock_);
 
     CDataStream ssValue(SER_DISK, CLIENT_VERSION);
-    ssValue.reserve(ssValue.GetSerializeSize(info));
+    ssValue.reserve(GetSerializeSize(info, SER_DISK, CLIENT_VERSION));
     ssValue << info;
     leveldb::Slice slice(&ssValue[0], ssValue.size());
 
     leveldb::Status status = db->Put(writeOptions, key.ToString(), slice);
-    HandleError(status);
+    dbwrapper_private::HandleError(status);
     return true;
 }
 
@@ -80,7 +80,7 @@ bool PaymentDisclosureDB::Get(const PaymentDisclosureKey& key, PaymentDisclosure
         if (status.IsNotFound())
             return false;
         LogPrintf("PaymentDisclosure: LevelDB read failure: %s\n", status.ToString());
-        HandleError(status);
+        dbwrapper_private::HandleError(status);
     }
 
     try {
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 21f880bcc..015c3519c 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -18,12 +18,13 @@ uint256 CBlockHeader::GetHash() const
 std::string CBlock::ToString() const
 {
     std::stringstream s;
-    s << strprintf("CBlock(hash=%s, ver=0x%08x, hashPrevBlock=%s, hashMerkleRoot=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%u)\n",
+    s << strprintf("CBlock(hash=%s, ver=0x%08x, hashPrevBlock=%s, hashMerkleRoot=%s, hashReserved=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%u)\n",
         GetHash().ToString(),
         nVersion,
         hashPrevBlock.ToString(),
         hashMerkleRoot.ToString(),
-        nTime, nBits, nNonce,
+        hashReserved.ToString(),
+        nTime, nBits, nNonce.ToString(),
         vtx.size());
     for (const auto& tx : vtx) {
         s << "  " << tx->ToString() << "\n";
diff --git a/src/primitives/block.h b/src/primitives/block.h
index 1fca55d91..672cff440 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -24,9 +24,11 @@ public:
     int32_t nVersion;
     uint256 hashPrevBlock;
     uint256 hashMerkleRoot;
+    uint256 hashReserved;
     uint32_t nTime;
     uint32_t nBits;
-    uint32_t nNonce;
+    uint256 nNonce;
+    std::vector<unsigned char> nSolution;
 
     CBlockHeader()
     {
@@ -40,9 +42,11 @@ public:
         READWRITE(this->nVersion);
         READWRITE(hashPrevBlock);
         READWRITE(hashMerkleRoot);
+        READWRITE(hashReserved);
         READWRITE(nTime);
         READWRITE(nBits);
         READWRITE(nNonce);
+        READWRITE(nSolution);
     }
 
     void SetNull()
@@ -50,9 +54,11 @@ public:
         nVersion = 0;
         hashPrevBlock.SetNull();
         hashMerkleRoot.SetNull();
+        hashReserved.SetNull();
         nTime = 0;
         nBits = 0;
-        nNonce = 0;
+        nNonce = uint256();
+        nSolution.clear();
     }
 
     bool IsNull() const
@@ -110,15 +116,44 @@ public:
         block.nVersion       = nVersion;
         block.hashPrevBlock  = hashPrevBlock;
         block.hashMerkleRoot = hashMerkleRoot;
+        block.hashReserved   = hashReserved;
         block.nTime          = nTime;
         block.nBits          = nBits;
         block.nNonce         = nNonce;
+        block.nSolution      = nSolution;
         return block;
     }
 
     std::string ToString() const;
 };
 
+/**
+ * Custom serializer for CBlockHeader that omits the nonce and solution, for use
+ * as input to Equihash.
+ */
+class CEquihashInput : private CBlockHeader
+{
+public:
+    CEquihashInput(const CBlockHeader &header)
+    {
+        CBlockHeader::SetNull();
+        *((CBlockHeader*)this) = header;
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+        inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(this->nVersion);
+        nVersion = this->nVersion;
+        READWRITE(hashPrevBlock);
+        READWRITE(hashMerkleRoot);
+        READWRITE(hashReserved);
+        READWRITE(nTime);
+        READWRITE(nBits);
+    }
+};
+
 /** Describes a place in the block chain to another node such that if the
  * other node doesn't have the same branch, it can find a recent common trunk.
  * The further back it is, the further before the fork it may be.
diff --git a/src/primitives/joinsplit.cpp b/src/primitives/joinsplit.cpp
new file mode 100644
index 000000000..366010255
--- /dev/null
+++ b/src/primitives/joinsplit.cpp
@@ -0,0 +1,98 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <primitives/joinsplit.h>
+#include <primitives/transaction.h>
+
+#include <hash.h>
+#include <tinyformat.h>
+#include <utilstrencodings.h>
+
+JSDescription::JSDescription(ZCJoinSplit& params,
+                             const uint256& pubKeyHash,
+                             const uint256& anchor,
+                             const std::array<libzcash::JSInput, ZC_NUM_JS_INPUTS>& inputs,
+                             const std::array<libzcash::JSOutput, ZC_NUM_JS_OUTPUTS>& outputs,
+                             CAmount vpub_old,
+                             CAmount vpub_new,
+                             bool computeProof,
+                             uint256 *esk // payment disclosure
+    ) : vpub_old(vpub_old), vpub_new(vpub_new), anchor(anchor)
+{
+    std::array<libzcash::Note, ZC_NUM_JS_OUTPUTS> notes;
+
+    proof = params.prove(
+        inputs,
+        outputs,
+        notes,
+        ciphertexts,
+        ephemeralKey,
+        pubKeyHash,
+        randomSeed,
+        macs,
+        nullifiers,
+        commitments,
+        vpub_old,
+        vpub_new,
+        anchor,
+        computeProof,
+        esk // payment disclosure
+        );
+}
+
+JSDescription JSDescription::Randomized(
+    ZCJoinSplit& params,
+    const uint256& pubKeyHash,
+    const uint256& anchor,
+    std::array<libzcash::JSInput, ZC_NUM_JS_INPUTS>& inputs,
+    std::array<libzcash::JSOutput, ZC_NUM_JS_OUTPUTS>& outputs,
+    std::array<size_t, ZC_NUM_JS_INPUTS>& inputMap,
+    std::array<size_t, ZC_NUM_JS_OUTPUTS>& outputMap,
+    CAmount vpub_old,
+    CAmount vpub_new,
+    bool computeProof,
+    uint256 *esk, // payment disclosure
+    std::function<int(int)> gen
+    )
+{
+    // Randomize the order of the inputs and outputs
+    inputMap = {0, 1};
+    outputMap = {0, 1};
+
+    assert(gen);
+
+    MappedShuffle(inputs.begin(), inputMap.begin(), ZC_NUM_JS_INPUTS, gen);
+    MappedShuffle(outputs.begin(), outputMap.begin(), ZC_NUM_JS_OUTPUTS, gen);
+
+    return JSDescription(
+        params, pubKeyHash, anchor, inputs, outputs,
+        vpub_old, vpub_new, computeProof,
+        esk // payment disclosure
+        );
+}
+
+bool JSDescription::Verify(
+    ZCJoinSplit& params,
+    libzcash::ProofVerifier& verifier,
+    const uint256& pubKeyHash
+    ) const {
+    return params.verify(
+        proof,
+        verifier,
+        pubKeyHash,
+        randomSeed,
+        macs,
+        nullifiers,
+        commitments,
+        vpub_old,
+        vpub_new,
+        anchor
+        );
+}
+
+uint256 JSDescription::h_sig(ZCJoinSplit& params, const uint256& pubKeyHash) const
+{
+    return params.h_sig(randomSeed, nullifiers, pubKeyHash);
+}
diff --git a/src/primitives/joinsplit.h b/src/primitives/joinsplit.h
new file mode 100644
index 000000000..1e6f4f65b
--- /dev/null
+++ b/src/primitives/joinsplit.h
@@ -0,0 +1,148 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Copyright (c) 2018      The Bitcoin Private developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BTCP_PRIMITIVES_JOINSPLIT_H
+#define BTCP_PRIMITIVES_JOINSPLIT_H
+
+#include "amount.h"
+#include "random.h"
+#include "script/script.h"
+#include "serialize.h"
+#include "uint256.h"
+#include "consensus/consensus.h"
+
+#include "zcash/NoteEncryption.hpp"
+#include "zcash/Zcash.h"
+#include "zcash/JoinSplit.hpp"
+#include "zcash/Proof.hpp"
+
+#include <boost/array.hpp>
+
+class JSDescription
+{
+public:
+    // These values 'enter from' and 'exit to' the value
+    // pool, respectively.
+    CAmount vpub_old;
+    CAmount vpub_new;
+
+    // JoinSplits are always anchored to a root in the note
+    // commitment tree at some point in the blockchain
+    // history or in the history of the current
+    // transaction.
+    uint256 anchor;
+
+    // Nullifiers are used to prevent double-spends. They
+    // are derived from the secrets placed in the note
+    // and the secret spend-authority key known by the
+    // spender.
+    std::array<uint256, ZC_NUM_JS_INPUTS> nullifiers;
+
+    // Note commitments are introduced into the commitment
+    // tree, blinding the public about the values and
+    // destinations involved in the JoinSplit. The presence of
+    // a commitment in the note commitment tree is required
+    // to spend it.
+    std::array<uint256, ZC_NUM_JS_OUTPUTS> commitments;
+
+    // Ephemeral key
+    uint256 ephemeralKey;
+
+    // Ciphertexts
+    // These contain trapdoors, values and other information
+    // that the recipient needs, including a memo field. It
+    // is encrypted using the scheme implemented in crypto/NoteEncryption.cpp
+    std::array<ZCNoteEncryption::Ciphertext, ZC_NUM_JS_OUTPUTS> ciphertexts = {{ {{0}} }};
+
+    // Random seed
+    uint256 randomSeed;
+
+    // MACs
+    // The verification of the JoinSplit requires these MACs
+    // to be provided as an input.
+    std::array<uint256, ZC_NUM_JS_INPUTS> macs;
+
+    // JoinSplit proof
+    // This is a zk-SNARK which ensures that this JoinSplit is valid.
+    libzcash::ZCProof proof;
+
+    JSDescription(): vpub_old(0), vpub_new(0) { }
+
+    JSDescription(ZCJoinSplit& params,
+                  const uint256& pubKeyHash,
+                  const uint256& rt,
+                  const std::array<libzcash::JSInput, ZC_NUM_JS_INPUTS>& inputs,
+                  const std::array<libzcash::JSOutput, ZC_NUM_JS_OUTPUTS>& outputs,
+                  CAmount vpub_old,
+                  CAmount vpub_new,
+                  bool computeProof = true, // Set to false in some tests
+                  uint256 *esk = nullptr // payment disclosure
+        );
+
+    static JSDescription Randomized(
+        ZCJoinSplit& params,
+        const uint256& pubKeyHash,
+        const uint256& rt,
+        std::array<libzcash::JSInput, ZC_NUM_JS_INPUTS>& inputs,
+        std::array<libzcash::JSOutput, ZC_NUM_JS_OUTPUTS>& outputs,
+        std::array<size_t, ZC_NUM_JS_INPUTS>& inputMap,
+        std::array<size_t, ZC_NUM_JS_OUTPUTS>& outputMap,
+        CAmount vpub_old,
+        CAmount vpub_new,
+        bool computeProof = true, // Set to false in some tests
+        uint256 *esk = nullptr, // payment disclosure
+        std::function<int(int)> gen = GetRandInt
+        );
+
+    // Verifies that the JoinSplit proof is correct.
+    bool Verify(
+        ZCJoinSplit& params,
+        libzcash::ProofVerifier& verifier,
+        const uint256& pubKeyHash
+        ) const;
+
+    // Returns the calculated h_sig
+    uint256 h_sig(ZCJoinSplit& params, const uint256& pubKeyHash) const;
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+        inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(vpub_old);
+        READWRITE(vpub_new);
+        READWRITE(anchor);
+        READWRITE(nullifiers);
+        READWRITE(commitments);
+        READWRITE(ephemeralKey);
+        READWRITE(randomSeed);
+        READWRITE(macs);
+        READWRITE(proof);
+        READWRITE(ciphertexts);
+    }
+
+    friend bool operator==(const JSDescription& a, const JSDescription& b)
+    {
+        return (
+            a.vpub_old == b.vpub_old &&
+            a.vpub_new == b.vpub_new &&
+            a.anchor == b.anchor &&
+            a.nullifiers == b.nullifiers &&
+            a.commitments == b.commitments &&
+            a.ephemeralKey == b.ephemeralKey &&
+            a.ciphertexts == b.ciphertexts &&
+            a.randomSeed == b.randomSeed &&
+            a.macs == b.macs &&
+            a.proof == b.proof
+            );
+    }
+
+    friend bool operator!=(const JSDescription& a, const JSDescription& b)
+    {
+        return !(a == b);
+    }
+};
+
+#endif
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index 230f762a1..4e632f9ae 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -55,7 +55,7 @@ std::string CTxOut::ToString() const
 }
 
 CMutableTransaction::CMutableTransaction() : nVersion(CTransaction::CURRENT_VERSION), nLockTime(0) {}
-CMutableTransaction::CMutableTransaction(const CTransaction& tx) : vin(tx.vin), vout(tx.vout), nVersion(tx.nVersion), nLockTime(tx.nLockTime) {}
+CMutableTransaction::CMutableTransaction(const CTransaction& tx) : vin(tx.vin), vout(tx.vout), nVersion(tx.nVersion), nLockTime(tx.nLockTime), vjoinsplit(tx.vjoinsplit), joinSplitPubKey(tx.joinSplitPubKey), joinSplitSig(tx.joinSplitSig) {}
 
 uint256 CMutableTransaction::GetHash() const
 {
@@ -76,9 +76,9 @@ uint256 CTransaction::ComputeWitnessHash() const
 }
 
 /* For backward compatibility, the hash is initialized to 0. TODO: remove the need for this default constructor entirely. */
-CTransaction::CTransaction() : vin(), vout(), nVersion(CTransaction::CURRENT_VERSION), nLockTime(0), hash{}, m_witness_hash{} {}
-CTransaction::CTransaction(const CMutableTransaction& tx) : vin(tx.vin), vout(tx.vout), nVersion(tx.nVersion), nLockTime(tx.nLockTime), hash{ComputeHash()}, m_witness_hash{ComputeWitnessHash()} {}
-CTransaction::CTransaction(CMutableTransaction&& tx) : vin(std::move(tx.vin)), vout(std::move(tx.vout)), nVersion(tx.nVersion), nLockTime(tx.nLockTime), hash{ComputeHash()}, m_witness_hash{ComputeWitnessHash()} {}
+CTransaction::CTransaction() : vin(), vout(), nVersion(CTransaction::CURRENT_VERSION), nLockTime(0), vjoinsplit(), joinSplitPubKey(), joinSplitSig(), hash{}, m_witness_hash{} {}
+CTransaction::CTransaction(const CMutableTransaction& tx) : vin(tx.vin), vout(tx.vout), nVersion(tx.nVersion), nLockTime(tx.nLockTime), vjoinsplit(tx.vjoinsplit), joinSplitPubKey(tx.joinSplitPubKey), joinSplitSig(tx.joinSplitSig), hash{ComputeHash()}, m_witness_hash{ComputeWitnessHash()} {}
+CTransaction::CTransaction(CMutableTransaction&& tx) : vin(std::move(tx.vin)), vout(std::move(tx.vout)), nVersion(tx.nVersion), nLockTime(tx.nLockTime), vjoinsplit(tx.vjoinsplit), joinSplitPubKey(tx.joinSplitPubKey), joinSplitSig(tx.joinSplitSig), hash{ComputeHash()}, m_witness_hash{ComputeWitnessHash()} {}
 
 CAmount CTransaction::GetValueOut() const
 {
@@ -88,9 +88,33 @@ CAmount CTransaction::GetValueOut() const
         if (!MoneyRange(tx_out.nValue) || !MoneyRange(nValueOut))
             throw std::runtime_error(std::string(__func__) + ": value out of range");
     }
+
+    for (std::vector<JSDescription>::const_iterator it(vjoinsplit.begin()); it != vjoinsplit.end(); ++it)
+    {
+        // NB: vpub_old "takes" money from the value pool just as outputs do
+        nValueOut += it->vpub_old;
+
+        if (!MoneyRange(it->vpub_old) || !MoneyRange(nValueOut))
+            throw std::runtime_error("CTransaction::GetValueOut(): value out of range");
+    }
     return nValueOut;
 }
 
+CAmount CTransaction::GetJoinSplitValueIn() const
+{
+    CAmount nValue = 0;
+    for (std::vector<JSDescription>::const_iterator it(vjoinsplit.begin()); it != vjoinsplit.end(); ++it)
+    {
+        // NB: vpub_new "gives" money to the value pool just as inputs do
+        nValue += it->vpub_new;
+
+        if (!MoneyRange(it->vpub_new) || !MoneyRange(nValue))
+            throw std::runtime_error("CTransaction::GetJoinSplitValueIn(): value out of range");
+    }
+
+    return nValue;
+}
+
 unsigned int CTransaction::GetTotalSize() const
 {
     return ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION);
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index 1c846d38e..d63d6b03c 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -12,6 +12,12 @@
 #include <serialize.h>
 #include <uint256.h>
 
+#include <primitives/joinsplit.h>
+#include <zcash/NoteEncryption.hpp>
+#include <zcash/Zcash.h>
+#include <zcash/JoinSplit.hpp>
+#include <zcash/Proof.hpp>
+
 static const int SERIALIZE_TRANSACTION_NO_WITNESS = 0x40000000;
 
 /** An outpoint - a combination of a transaction hash and an index n into its vout */
@@ -226,6 +232,13 @@ inline void UnserializeTransaction(TxType& tx, Stream& s) {
         throw std::ios_base::failure("Unknown transaction optional data");
     }
     s >> tx.nLockTime;
+    if(tx.nVersion >= 2) {
+        s >> tx.vjoinsplit;
+        if (tx.vjoinsplit.size() > 0) {
+            s >> tx.joinSplitPubKey;
+            s >> tx.joinSplitSig;
+        }
+    }
 }
 
 template<typename Stream, typename TxType>
@@ -255,6 +268,13 @@ inline void SerializeTransaction(const TxType& tx, Stream& s) {
         }
     }
     s << tx.nLockTime;
+    if(tx.nVersion >= 2) {
+        s << tx.vjoinsplit;
+        if (tx.vjoinsplit.size() > 0) {
+            s << tx.joinSplitPubKey;
+            s << tx.joinSplitSig;
+        }
+    }
 }
 
 
@@ -264,6 +284,8 @@ inline void SerializeTransaction(const TxType& tx, Stream& s) {
 class CTransaction
 {
 public:
+    typedef std::array<unsigned char, 64> joinsplit_sig_t;
+
     // Default transaction version.
     static const int32_t CURRENT_VERSION=2;
 
@@ -282,6 +304,10 @@ public:
     const std::vector<CTxOut> vout;
     const int32_t nVersion;
     const uint32_t nLockTime;
+    const std::vector<JSDescription> vjoinsplit;
+    const uint256 joinSplitPubKey;
+    const joinsplit_sig_t joinSplitSig = {{0}};
+
 
 private:
     /** Memory only. */
@@ -321,6 +347,9 @@ public:
     // GetValueIn() is a method on CCoinsViewCache, because
     // inputs must be known to compute value in.
 
+    // Return sum of JoinSplit vpub_new
+    CAmount GetJoinSplitValueIn() const;
+
     /**
      * Get the total transaction size in bytes, including witness data.
      * "Total Size" defined in BIP141 and BIP144.
@@ -363,6 +392,9 @@ struct CMutableTransaction
     std::vector<CTxOut> vout;
     int32_t nVersion;
     uint32_t nLockTime;
+    std::vector<JSDescription> vjoinsplit;
+    uint256 joinSplitPubKey;
+    CTransaction::joinsplit_sig_t joinSplitSig = {{0}};
 
     CMutableTransaction();
     explicit CMutableTransaction(const CTransaction& tx);
diff --git a/src/random.h b/src/random.h
index 1d6b13a53..940e525bd 100644
--- a/src/random.h
+++ b/src/random.h
@@ -12,6 +12,7 @@
 
 #include <stdint.h>
 #include <limits>
+#include <functional>
 
 /* Seed OpenSSL PRNG with additional entropy data */
 void RandAddSeed();
@@ -150,4 +151,34 @@ bool Random_SanityCheck();
 /** Initialize the RNG. */
 void RandomInit();
 
+/**
+ * Identity function for MappedShuffle, so that elements retain their original order.
+ */
+int GenIdentity(int n);
+
+/**
+ * Rearranges the elements in the range [first,first+len) randomly, assuming
+ * that gen is a uniform random number generator. Follows the same algorithm as
+ * std::shuffle in C++11 (a Durstenfeld shuffle).
+ *
+ * The elements in the range [mapFirst,mapFirst+len) are rearranged according to
+ * the same permutation, enabling the permutation to be tracked by the caller.
+ *
+ * gen takes an integer n and produces a uniform random output in [0,n).
+ */
+template <typename RandomAccessIterator, typename MapRandomAccessIterator>
+    void MappedShuffle(RandomAccessIterator first,
+                       MapRandomAccessIterator mapFirst,
+                       size_t len,
+                       std::function<int(int)> gen)
+{
+    for (size_t i = len-1; i > 0; --i) {
+        auto r = gen(i+1);
+        assert(r >= 0);
+        assert(r <= i);
+        std::swap(first[i], first[r]);
+        std::swap(mapFirst[i], mapFirst[r]);
+    }
+}
+
 #endif // BITCOIN_RANDOM_H
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 24fb522e6..29d87ebb7 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -101,7 +101,7 @@ UniValue blockheaderToJSON(const CBlockIndex* blockindex)
     result.pushKV("merkleroot", blockindex->hashMerkleRoot.GetHex());
     result.pushKV("time", (int64_t)blockindex->nTime);
     result.pushKV("mediantime", (int64_t)blockindex->GetMedianTimePast());
-    result.pushKV("nonce", (uint64_t)blockindex->nNonce);
+    result.pushKV("nonce", blockindex->nNonce.GetHex());
     result.pushKV("bits", strprintf("%08x", blockindex->nBits));
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
@@ -146,7 +146,7 @@ UniValue blockToJSON(const CBlock& block, const CBlockIndex* blockindex, bool tx
     result.pushKV("tx", txs);
     result.pushKV("time", block.GetBlockTime());
     result.pushKV("mediantime", (int64_t)blockindex->GetMedianTimePast());
-    result.pushKV("nonce", (uint64_t)block.nNonce);
+    result.pushKV("nonce", block.nNonce.GetHex());
     result.pushKV("bits", strprintf("%08x", block.nBits));
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 203fac39e..a024ffef6 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -10,6 +10,7 @@
 #include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
+#include <crypto/equihash.h>
 #include <init.h>
 #include <validation.h>
 #include <key_io.h>
@@ -116,6 +117,8 @@ UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGen
     }
     unsigned int nExtraNonce = 0;
     UniValue blockHashes(UniValue::VARR);
+    unsigned int n = Params().EquihashN();
+    unsigned int k = Params().EquihashK();
     while (nHeight < nHeightEnd && !ShutdownRequested())
     {
         std::unique_ptr<CBlockTemplate> pblocktemplate(BlockAssembler(Params()).CreateNewBlock(coinbaseScript->reserveScript));
@@ -126,16 +129,52 @@ UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGen
             LOCK(cs_main);
             IncrementExtraNonce(pblock, chainActive.Tip(), nExtraNonce);
         }
-        while (nMaxTries > 0 && pblock->nNonce < nInnerLoopCount && !CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
-            ++pblock->nNonce;
+
+        // Hash state
+        crypto_generichash_blake2b_state eh_state;
+        EhInitialiseState(n, k, eh_state);
+
+        // I = the block header minus nonce and solution.
+        CEquihashInput I{*pblock};
+        CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+        ss << I;
+
+        // H(I||...
+        crypto_generichash_blake2b_update(&eh_state, (unsigned char*)&ss[0], ss.size());
+
+        while (nMaxTries > 0 && UintToArith256(pblock->nNonce) < nInnerLoopCount) {
+            // Yes, there is a chance every nonce could fail to satisfy the -regtest
+            // target -- 1 in 2^(2^256). That ain't gonna happen
+            pblock->nNonce = ArithToUint256(UintToArith256(pblock->nNonce) + 1);
             --nMaxTries;
+
+            // H(I||V||...
+            crypto_generichash_blake2b_state curr_state;
+            curr_state = eh_state;
+            crypto_generichash_blake2b_update(&curr_state,
+                                              pblock->nNonce.begin(),
+                                              pblock->nNonce.size());
+
+            // (x_1, x_2, ...) = A(I, V, n, k)
+            std::function<bool(std::vector<unsigned char>)> validBlock =
+                [&pblock](std::vector<unsigned char> soln) {
+                pblock->nSolution = soln;
+                return CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus());
+            };
+            bool found = EhBasicSolveUncancellable(n, k, curr_state, validBlock);
+            if (found) {
+                goto endloop;
+            }
         }
+
         if (nMaxTries == 0) {
             break;
         }
-        if (pblock->nNonce == nInnerLoopCount) {
+        if (UintToArith256(pblock->nNonce) == nInnerLoopCount) {
             continue;
         }
+
+    endloop:
         std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(*pblock);
         if (!ProcessNewBlock(Params(), shared_pblock, true, nullptr))
             throw JSONRPCError(RPC_INTERNAL_ERROR, "ProcessNewBlock, block not accepted");
@@ -531,7 +570,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
 
     // Update nTime
     UpdateTime(pblock, consensusParams, pindexPrev);
-    pblock->nNonce = 0;
+    pblock->nNonce = uint256();
 
     // NOTE: If at some point we support pre-segwit miners post-segwit-activation, this needs to take segwit support into consideration
     const bool fPreSegWit = (ThresholdState::ACTIVE != VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT, versionbitscache));
diff --git a/src/serialize.h b/src/serialize.h
index e54c7483d..78459f63e 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -24,6 +24,9 @@
 #include <prevector.h>
 #include <span.h>
 
+#include <boost/array.hpp>
+#include <boost/optional.hpp>
+
 static const unsigned int MAX_SIZE = 0x02000000;
 
 /**
@@ -173,11 +176,11 @@ template<typename X> const X& ReadWriteAsHelper(const X& x) { return x; }
 #define READWRITE(...) (::SerReadWriteMany(s, ser_action, __VA_ARGS__))
 #define READWRITEAS(type, obj) (::SerReadWriteMany(s, ser_action, ReadWriteAsHelper<type>(obj)))
 
-/** 
+/**
  * Implement three methods for serializable objects. These are actually wrappers over
  * "SerializationOp" template, which implements the body of each class' serialization
  * code. Adding "ADD_SERIALIZE_METHODS" in the body of the class causes these wrappers to be
- * added as members. 
+ * added as members.
  */
 #define ADD_SERIALIZE_METHODS                                         \
     template<typename Stream>                                         \
@@ -308,16 +311,16 @@ uint64_t ReadCompactSize(Stream& is)
  * sure the encoding is one-to-one, one is subtracted from all but the last digit.
  * Thus, the byte sequence a[] with length len, where all but the last byte
  * has bit 128 set, encodes the number:
- * 
+ *
  *  (a[len-1] & 0x7F) + sum(i=1..len-1, 128^i*((a[len-i-1] & 0x7F)+1))
- * 
+ *
  * Properties:
  * * Very small (0-127: 1 byte, 128-16511: 2 bytes, 16512-2113663: 3 bytes)
  * * Every integer has exactly one encoding
  * * Encoding does not depend on size of original integer type
  * * No redundancy: every (infinite) byte sequence corresponds to a list
  *   of encoded integers.
- * 
+ *
  * 0:         [0x00]  256:        [0x81 0x00]
  * 1:         [0x01]  16383:      [0xFE 0x7F]
  * 127:       [0x7F]  16384:      [0xFF 0x00]
@@ -546,12 +549,24 @@ template<typename Stream, typename T, typename A> void Unserialize_impl(Stream&
 template<typename Stream, typename T, typename A, typename V> void Unserialize_impl(Stream& is, std::vector<T, A>& v, const V&);
 template<typename Stream, typename T, typename A> inline void Unserialize(Stream& is, std::vector<T, A>& v);
 
+/**
+ * array
+ */
+template<typename Stream, typename T, std::size_t N> void Serialize(Stream& os, const std::array<T, N>& item);
+template<typename Stream, typename T, std::size_t N> void Unserialize(Stream& is, std::array<T, N>& item);
+
 /**
  * pair
  */
 template<typename Stream, typename K, typename T> void Serialize(Stream& os, const std::pair<K, T>& item);
 template<typename Stream, typename K, typename T> void Unserialize(Stream& is, std::pair<K, T>& item);
 
+/**
+ * optional
+ */
+template<typename Stream, typename T> void Serialize(Stream& os, const boost::optional<T>& item);
+template<typename Stream, typename T> void Unserialize(Stream& is, boost::optional<T>& item);
+
 /**
  * map
  */
@@ -753,6 +768,24 @@ inline void Unserialize(Stream& is, std::vector<T, A>& v)
     Unserialize_impl(is, v, T());
 }
 
+/**
+ * array
+ */
+template<typename Stream, typename T, std::size_t N>
+    void Serialize(Stream& os, const std::array<T, N>& item)
+{
+    for (size_t i = 0; i < N; i++) {
+        Serialize(os, item[i]);
+    }
+}
+
+template<typename Stream, typename T, std::size_t N>
+    void Unserialize(Stream& is, std::array<T, N>& item)
+{
+    for (size_t i = 0; i < N; i++) {
+        Unserialize(is, item[i]);
+    }
+}
 
 
 /**
@@ -773,6 +806,41 @@ void Unserialize(Stream& is, std::pair<K, T>& item)
 }
 
 
+/**
+ * optional
+ */
+template<typename Stream, typename T>
+    void Serialize(Stream& os, const boost::optional<T>& item)
+{
+    // If the value is there, put 0x01 and then serialize the value.
+    // If it's not, put 0x00.
+    if (item) {
+        unsigned char discriminant = 0x01;
+        Serialize(os, discriminant);
+        Serialize(os, *item);
+    } else {
+        unsigned char discriminant = 0x00;
+        Serialize(os, discriminant);
+    }
+}
+
+template<typename Stream, typename T>
+    void Unserialize(Stream& is, boost::optional<T>& item)
+{
+    unsigned char discriminant = 0x00;
+    Unserialize(is, discriminant);
+
+    if (discriminant == 0x00) {
+        item = boost::none;
+    } else if (discriminant == 0x01) {
+        T object;
+        Unserialize(is, object);
+        item = object;
+    } else {
+        throw std::ios_base::failure("non-canonical optional discriminant");
+    }
+}
+
 
 /**
  * map
diff --git a/src/test/sha256compress_tests.cpp b/src/test/sha256compress_tests.cpp
new file mode 100644
index 000000000..5a2c31d9a
--- /dev/null
+++ b/src/test/sha256compress_tests.cpp
@@ -0,0 +1,86 @@
+#include <test/test_bitcoin.h>
+#include <crypto/sha256.h>
+#include <uint256.h>
+
+#include <stdexcept>
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_FIXTURE_TEST_SUITE(sha256compress_tests, BasicTestingSetup)
+
+BOOST_AUTO_TEST_CASE(compression)
+{
+	{
+		unsigned char preimage[64] = {};
+		CSHA256 hasher;
+		hasher.Write(&preimage[0], 64);
+
+		uint256 digest;
+
+		hasher.FinalizeNoPadding(digest.begin());
+
+		BOOST_CHECK_MESSAGE(digest == uint256S("d8a93718eaf9feba4362d2c091d4e58ccabe9f779957336269b4b917be9856da"),
+			                digest.GetHex());
+	}
+
+	{
+		unsigned char preimage[63] = {};
+		CSHA256 hasher;
+		hasher.Write(&preimage[0], 63);
+		uint256 digest;
+		BOOST_CHECK_THROW(hasher.FinalizeNoPadding(digest.begin()), std::length_error);
+	}
+
+	{
+		unsigned char preimage[65] = {};
+		CSHA256 hasher;
+		hasher.Write(&preimage[0], 65);
+		uint256 digest;
+		BOOST_CHECK_THROW(hasher.FinalizeNoPadding(digest.begin()), std::length_error);
+	}
+
+	{
+		unsigned char n = 0x00;
+		CSHA256 hasher;
+		for (size_t i = 0; i < 64; i++) {
+			hasher.Write(&n, 1);
+		}
+		uint256 digest;
+
+		hasher.FinalizeNoPadding(digest.begin());
+
+		BOOST_CHECK_MESSAGE(digest == uint256S("d8a93718eaf9feba4362d2c091d4e58ccabe9f779957336269b4b917be9856da"),
+			                digest.GetHex());
+	}
+
+    {
+        unsigned char preimage[64] = { 'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd',
+                                       'a', 'b', 'c', 'd'
+                                    };
+		CSHA256 hasher;
+        hasher.Write(&preimage[0], 64);
+
+        uint256 digest;
+
+        hasher.FinalizeNoPadding(digest.begin());
+
+        BOOST_CHECK_MESSAGE(digest == uint256S("da70ec41879e36b000281733d4deb27ddf41e8e343a38f2fabbd2d8611987d86"),
+            digest.GetHex());
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/validation_block_tests.cpp b/src/test/validation_block_tests.cpp
index 37c4f7913..306f723e1 100644
--- a/src/test/validation_block_tests.cpp
+++ b/src/test/validation_block_tests.cpp
@@ -72,7 +72,7 @@ std::shared_ptr<CBlock> FinalizeBlock(std::shared_ptr<CBlock> pblock)
     pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
 
     while (!CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
-        ++(pblock->nNonce);
+        pblock->nNonce = ArithToUint256(UintToArith256(pblock->nNonce) + 1);
     }
 
     return pblock;
diff --git a/src/uint252.h b/src/uint252.h
new file mode 100644
index 000000000..e7b98ddf0
--- /dev/null
+++ b/src/uint252.h
@@ -0,0 +1,50 @@
+#ifndef UINT252_H
+#define UINT252_H
+
+#include <vector>
+#include "uint256.h"
+#include "serialize.h"
+
+// Wrapper of uint256 with guarantee that first
+// four bits are zero.
+class uint252 {
+private:
+    uint256 contents;
+
+public:
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(contents);
+
+        if ((*contents.begin()) & 0xF0) {
+            throw std::ios_base::failure("spending key has invalid leading bits");
+        }
+    }
+
+    const unsigned char* begin() const
+    {
+        return contents.begin();
+    }
+
+    const unsigned char* end() const
+    {
+        return contents.end();
+    }
+
+    uint252() : contents() {};
+    explicit uint252(const uint256& in) : contents(in) {
+        if (*contents.begin() & 0xF0) {
+            throw std::domain_error("leading bits are set in argument given to uint252 constructor");
+        }
+    }
+
+    uint256 inner() const {
+        return contents;
+    }
+
+    friend inline bool operator==(const uint252& a, const uint252& b) { return a.contents == b.contents; }
+};
+
+#endif
diff --git a/src/util.cpp b/src/util.cpp
index 34483d95b..8e9b35899 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -726,8 +726,58 @@ static fs::path g_blocks_path_cached;
 static fs::path g_blocks_path_cache_net_specific;
 static fs::path pathCached;
 static fs::path pathCachedNetSpecific;
+static boost::filesystem::path zc_paramsPathCached;
 static CCriticalSection csPathCached;
 
+static boost::filesystem::path ZC_GetBaseParamsDir()
+{
+    // Copied from GetDefaultDataDir and adapter for zcash params.
+
+    namespace fs = boost::filesystem;
+    // Windows < Vista: C:\Documents and Settings\Username\Application Data\ZcashParams
+    // Windows >= Vista: C:\Users\Username\AppData\Roaming\ZcashParams
+    // Mac: ~/Library/Application Support/ZcashParams
+    // Unix: ~/.zcash-params
+#ifdef WIN32
+    // Windows
+    return GetSpecialFolderPath(CSIDL_APPDATA) / "ZcashParams";
+#else
+    fs::path pathRet;
+    char* pszHome = getenv("HOME");
+    if (pszHome == NULL || strlen(pszHome) == 0)
+        pathRet = fs::path("/");
+    else
+        pathRet = fs::path(pszHome);
+#ifdef MAC_OSX
+    // Mac
+    pathRet /= "Library/Application Support";
+    TryCreateDirectory(pathRet);
+    return pathRet / "ZcashParams";
+#else
+    // Unix
+    return pathRet / ".zcash-params";
+#endif
+#endif
+}
+
+const boost::filesystem::path &ZC_GetParamsDir()
+{
+    namespace fs = boost::filesystem;
+
+    LOCK(csPathCached); // Reuse the same lock as upstream.
+
+    fs::path &path = zc_paramsPathCached;
+
+    // This can be called during exceptions by LogPrintf(), so we cache the
+    // value so we don't have to do memory allocations after that.
+    if (!path.empty())
+        return path;
+
+    path = ZC_GetBaseParamsDir();
+
+    return path;
+}
+
 const fs::path &GetBlocksDir(bool fNetSpecific)
 {
 
diff --git a/src/util.h b/src/util.h
index efd8a4bd9..1a37d4f3a 100644
--- a/src/util.h
+++ b/src/util.h
@@ -70,6 +70,8 @@ bool error(const char* fmt, const Args&... args)
     return false;
 }
 
+const boost::filesystem::path &ZC_GetParamsDir();
+
 void PrintExceptionContinue(const std::exception *pex, const char* pszThread);
 bool FileCommit(FILE *file);
 bool TruncateFile(FILE *file, unsigned int length);
diff --git a/src/wallet/asyncrpcoperation_sendmany.cpp b/src/wallet/asyncrpcoperation_sendmany.cpp
index 281433b0b..3a57fdf49 100644
--- a/src/wallet/asyncrpcoperation_sendmany.cpp
+++ b/src/wallet/asyncrpcoperation_sendmany.cpp
@@ -2,27 +2,27 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "asyncrpcoperation_sendmany.h"
-#include "asyncrpcqueue.h"
-#include "amount.h"
-#include "consensus/upgrades.h"
-#include "core_io.h"
-#include "init.h"
-#include "main.h"
-#include "net.h"
-#include "netbase.h"
-#include "rpcserver.h"
-#include "timedata.h"
-#include "util.h"
-#include "utilmoneystr.h"
-#include "wallet.h"
-#include "walletdb.h"
-#include "script/interpreter.h"
-#include "utiltime.h"
-#include "rpcprotocol.h"
-#include "zcash/IncrementalMerkleTree.hpp"
-#include "sodium.h"
-#include "miner.h"
+#include <asyncrpcoperation_sendmany.h>
+#include <asyncrpcqueue.h>
+#include <amount.h>
+#include <consensus/upgrades.h>
+#include <core_io.h>
+#include <init.h>
+#include <net.h>
+#include <netbase.h>
+#include <rpcserver.h>
+#include <timedata.h>
+#include <util.h>
+#include <utilmoneystr.h>
+#include <wallet.h>
+#include <walletdb.h>
+#include <script/interpreter.h>
+#include <utiltime.h>
+#include <validation.h>
+#include <rpcprotocol.h>
+#include <zcash/IncrementalMerkleTree.hpp>
+#include <sodium.h>
+#include <miner.h>
 
 #include <iostream>
 #include <chrono>
@@ -65,15 +65,15 @@ AsyncRPCOperation_sendmany::AsyncRPCOperation_sendmany(
     if (minDepth < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Minconf cannot be negative");
     }
-    
+
     if (fromAddress.size() == 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "From address parameter missing");
     }
-    
+
     if (tOutputs.size() == 0 && zOutputs.size() == 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "No recipients");
     }
-    
+
     fromtaddr_ = CBitcoinAddress(fromAddress);
     isfromtaddr_ = fromtaddr_.IsValid();
     isfromzaddr_ = false;
@@ -88,7 +88,7 @@ AsyncRPCOperation_sendmany::AsyncRPCOperation_sendmany(
             if (!pwalletMain->GetSpendingKey(addr, key)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid from address, no spending key found for zaddr");
             }
-            
+
             isfromzaddr_ = true;
             frompaymentaddress_ = addr;
             spendingkey_ = key;
@@ -224,9 +224,9 @@ bool AsyncRPCOperation_sendmany::main_impl() {
                     throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, "Could not find any non-coinbase UTXOs to spend.");
                 }
             }
-        }        
+        }
     }
-    
+
     if (isfromzaddr_ && !find_unspent_notes()) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, "Insufficient funds, no unspent notes found for zaddr from address.");
     }
@@ -262,7 +262,7 @@ bool AsyncRPCOperation_sendmany::main_impl() {
             strprintf("Insufficient transparent funds, have %s, need %s",
             FormatMoney(t_inputs_total), FormatMoney(targetAmount)));
     }
-    
+
     if (isfromzaddr_ && (z_inputs_total < targetAmount)) {
         throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS,
             strprintf("Insufficient protected funds, have %s, need %s",
@@ -351,18 +351,18 @@ bool AsyncRPCOperation_sendmany::main_impl() {
 
     /**
      * SCENARIO #1
-     * 
+     *
      * taddr -> taddrs
-     * 
+     *
      * There are no zaddrs or joinsplits involved.
      */
     if (isPureTaddrOnlyTx) {
         add_taddr_outputs_to_tx();
-        
+
         CAmount funds = selectedUTXOAmount;
         CAmount fundsSpent = t_outputs_total + minersFee;
         CAmount change = funds - fundsSpent;
-        
+
         if (change > 0) {
             add_taddr_change_output_to_tx(change);
 
@@ -371,7 +371,7 @@ bool AsyncRPCOperation_sendmany::main_impl() {
                     FormatMoney(change)
                     );
         }
-        
+
         UniValue obj(UniValue::VOBJ);
         obj.push_back(Pair("rawtxn", EncodeHexTx(tx_)));
         sign_send_raw_transaction(obj);
@@ -381,7 +381,7 @@ bool AsyncRPCOperation_sendmany::main_impl() {
      * END SCENARIO #1
      */
 
-    
+
     // Prepare raw transaction to handle JoinSplits
     CMutableTransaction mtx(tx_);
     crypto_sign_keypair(joinSplitPubKey_.begin(), joinSplitPrivKey_);
@@ -421,10 +421,10 @@ bool AsyncRPCOperation_sendmany::main_impl() {
 
     /**
      * SCENARIO #2
-     * 
+     *
      * taddr -> taddrs
      *       -> zaddrs
-     * 
+     *
      * Note: Consensus rule states that coinbase utxos can only be sent to a zaddr.
      *       Local wallet rule does not allow any change when sending coinbase utxos
      *       since there is currently no way to specify a change address and we don't
@@ -432,11 +432,11 @@ bool AsyncRPCOperation_sendmany::main_impl() {
      */
     if (isfromtaddr_) {
         add_taddr_outputs_to_tx();
-        
+
         CAmount funds = selectedUTXOAmount;
         CAmount fundsSpent = t_outputs_total + minersFee + z_outputs_total;
         CAmount change = funds - fundsSpent;
-        
+
         if (change > 0) {
             if (selectedUTXOCoinbase) {
                 assert(isSingleZaddrOutput);
@@ -473,7 +473,7 @@ bool AsyncRPCOperation_sendmany::main_impl() {
                     jso.memo = get_memo_from_hex_string(hexMemo);
                 }
                 info.vjsout.push_back(jso);
-                
+
                 // Funds are removed from the value pool and enter the private pool
                 info.vpub_old += value;
             }
@@ -484,16 +484,16 @@ bool AsyncRPCOperation_sendmany::main_impl() {
     }
     /**
      * END SCENARIO #2
-     */   
- 
-    
-    
+     */
+
+
+
     /**
      * SCENARIO #3
-     * 
+     *
      * zaddr -> taddrs
      *       -> zaddrs
-     * 
+     *
      * Send to zaddrs by chaining JoinSplits together and immediately consuming any change
      * Send to taddrs by creating dummy z outputs and accumulating value in a change note
      * which is used to set vpub_new in the last chained joinsplit.
@@ -619,9 +619,9 @@ bool AsyncRPCOperation_sendmany::main_impl() {
 
             vOutPoints.push_back(jso);
             vInputNotes.push_back(note);
-            
+
             jsInputValue += noteFunds;
-            
+
             int wtxHeight = -1;
             int wtxDepth = -1;
             {
@@ -644,14 +644,14 @@ bool AsyncRPCOperation_sendmany::main_impl() {
                     wtxDepth
                     );
         }
-                    
+
         // Add history of previous commitments to witness
         if (vInputNotes.size() > 0) {
 
             if (vInputWitnesses.size()==0) {
                 throw JSONRPCError(RPC_WALLET_ERROR, "Could not find witness for note commitment");
             }
-            
+
             for (auto & optionalWitness : vInputWitnesses) {
                 if (!optionalWitness) {
                     throw JSONRPCError(RPC_WALLET_ERROR, "Witness for note commitment is null");
@@ -766,7 +766,7 @@ bool AsyncRPCOperation_sendmany::main_impl() {
  * Raw transaction as hex string should be in object field "rawtxn"
  */
 void AsyncRPCOperation_sendmany::sign_send_raw_transaction(UniValue obj)
-{   
+{
     // Sign the raw transaction
     UniValue rawtxnValue = find_value(obj, "rawtxn");
     if (rawtxnValue.isNull()) {
@@ -861,7 +861,7 @@ bool AsyncRPCOperation_sendmany::find_utxos(bool fAcceptCoinbase=false) {
         if (isCoinbase && fAcceptCoinbase==false) {
             continue;
         }
-        
+
         CAmount nValue = out.tx->vout[out.i].nValue;
         SendManyInputUTXO utxo(out.tx->GetHash(), out.i, nValue, isCoinbase);
         t_inputs_.push_back(utxo);
@@ -895,7 +895,7 @@ bool AsyncRPCOperation_sendmany::find_unspent_notes() {
             HexStr(data).substr(0, 10)
             );
     }
-    
+
     if (z_inputs_.size() == 0) {
         return false;
     }
@@ -1136,7 +1136,7 @@ void AsyncRPCOperation_sendmany::add_taddr_change_output_to_tx(CAmount amount) {
 
 boost::array<unsigned char, ZC_MEMO_SIZE> AsyncRPCOperation_sendmany::get_memo_from_hex_string(std::string s) {
     boost::array<unsigned char, ZC_MEMO_SIZE> memo = {{0x00}};
-    
+
     std::vector<unsigned char> rawMemo = ParseHex(s.c_str());
 
     // If ParseHex comes across a non-hex char, it will stop but still return results so far.
@@ -1144,11 +1144,11 @@ boost::array<unsigned char, ZC_MEMO_SIZE> AsyncRPCOperation_sendmany::get_memo_f
     if (slen % 2 !=0 || (slen>0 && rawMemo.size()!=slen/2)) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Memo must be in hexadecimal format");
     }
-    
+
     if (rawMemo.size() > ZC_MEMO_SIZE) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Memo size of %d is too big, maximum allowed is %d", rawMemo.size(), ZC_MEMO_SIZE));
     }
-    
+
     // copy vector into boost array
     int lenMemo = rawMemo.size();
     for (int i = 0; i < ZC_MEMO_SIZE && i < lenMemo; i++) {
@@ -1171,4 +1171,3 @@ UniValue AsyncRPCOperation_sendmany::getStatus() const {
     obj.push_back(Pair("params", contextinfo_ ));
     return obj;
 }
-
diff --git a/src/wallet/asyncrpcoperation_shieldcoinbase.cpp b/src/wallet/asyncrpcoperation_shieldcoinbase.cpp
index 6aef57949..6c4032083 100644
--- a/src/wallet/asyncrpcoperation_shieldcoinbase.cpp
+++ b/src/wallet/asyncrpcoperation_shieldcoinbase.cpp
@@ -2,26 +2,26 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "asyncrpcqueue.h"
-#include "amount.h"
-#include "consensus/upgrades.h"
-#include "core_io.h"
-#include "init.h"
-#include "main.h"
-#include "net.h"
-#include "netbase.h"
-#include "rpcserver.h"
-#include "timedata.h"
-#include "util.h"
-#include "utilmoneystr.h"
-#include "wallet.h"
-#include "walletdb.h"
-#include "script/interpreter.h"
-#include "utiltime.h"
-#include "rpcprotocol.h"
-#include "zcash/IncrementalMerkleTree.hpp"
-#include "sodium.h"
-#include "miner.h"
+#include <asyncrpcqueue.h>
+#include <amount.h>
+#include <consensus/upgrades.h>
+#include <core_io.h>
+#include <init.h>
+#include <main.h>
+#include <net.h>
+#include <netbase.h>
+#include <rpcserver.h>
+#include <timedata.h>
+#include <util.h>
+#include <utilmoneystr.h>
+#include <wallet.h>
+#include <walletdb.h>
+#include <script/interpreter.h>
+#include <utiltime.h>
+#include <rpcprotocol.h>
+#include <zcash/IncrementalMerkleTree.hpp>
+#include <sodium.h>
+#include <miner.h>
 
 #include <iostream>
 #include <chrono>
diff --git a/src/wallet/asyncrpcoperation_shieldcoinbase.h b/src/wallet/asyncrpcoperation_shieldcoinbase.h
index c7faf28e8..dd60cc3f3 100644
--- a/src/wallet/asyncrpcoperation_shieldcoinbase.h
+++ b/src/wallet/asyncrpcoperation_shieldcoinbase.h
@@ -5,13 +5,13 @@
 #ifndef ASYNCRPCOPERATION_SHIELDCOINBASE_H
 #define ASYNCRPCOPERATION_SHIELDCOINBASE_H
 
-#include "asyncrpcoperation.h"
-#include "amount.h"
-#include "base58.h"
-#include "primitives/transaction.h"
-#include "zcash/JoinSplit.hpp"
-#include "zcash/Address.hpp"
-#include "wallet.h"
+#include <asyncrpcoperation.h>
+#include <amount.h>
+#include <base58.h>
+#include <primitives/transaction.h>
+#include <zcash/JoinSplit.hpp>
+#include <zcash/Address.hpp>
+#include <wallet.h>
 
 #include <unordered_map>
 #include <tuple>
@@ -126,4 +126,3 @@ public:
 
 
 #endif /* ASYNCRPCOPERATION_SHIELDCOINBASE_H */
-
diff --git a/src/wallet/joinsplit.h b/src/wallet/joinsplit.h
new file mode 100644
index 000000000..f66e36930
--- /dev/null
+++ b/src/wallet/joinsplit.h
@@ -0,0 +1,139 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_WALLET_JOINSPLIT_H
+#define BITCOIN_WALLET_JOINSPLIT_H
+
+#include <uint256.h>
+#include <zcash/Address.hpp>
+
+/** A note outpoint */
+class JSOutPoint
+{
+public:
+    // Transaction hash
+    uint256 hash;
+    // Index into CTransaction.vjoinsplit
+    size_t js;
+    // Index into JSDescription fields of length ZC_NUM_JS_OUTPUTS
+    uint8_t n;
+
+    JSOutPoint() { SetNull(); }
+JSOutPoint(uint256 h, size_t js, uint8_t n) : hash {h}, js {js}, n {n} { }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+        inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+        READWRITE(hash);
+        READWRITE(js);
+        READWRITE(n);
+    }
+
+    void SetNull() { hash.SetNull(); }
+    bool IsNull() const { return hash.IsNull(); }
+
+    friend bool operator<(const JSOutPoint& a, const JSOutPoint& b) {
+        return (a.hash < b.hash ||
+                (a.hash == b.hash && a.js < b.js) ||
+                (a.hash == b.hash && a.js == b.js && a.n < b.n));
+    }
+
+    friend bool operator==(const JSOutPoint& a, const JSOutPoint& b) {
+        return (a.hash == b.hash && a.js == b.js && a.n == b.n);
+    }
+
+    friend bool operator!=(const JSOutPoint& a, const JSOutPoint& b) {
+        return !(a == b);
+    }
+
+    std::string ToString() const;
+};
+
+class CNoteData
+{
+public:
+    libzcash::PaymentAddress address;
+
+    /**
+     * Cached note nullifier. May not be set if the wallet was not unlocked when
+     * this was CNoteData was created. If not set, we always assume that the
+     * note has not been spent.
+     *
+     * It's okay to cache the nullifier in the wallet, because we are storing
+     * the spending key there too, which could be used to derive this.
+     * If the wallet is encrypted, this means that someone with access to the
+     * locked wallet cannot spend notes, but can connect received notes to the
+     * transactions they are spent in. This is the same security semantics as
+     * for transparent addresses.
+     */
+    boost::optional<uint256> nullifier;
+
+    /**
+     * Cached incremental witnesses for spendable Notes.
+     * Beginning of the list is the most recent witness.
+     */
+    std::list<ZCIncrementalWitness> witnesses;
+
+    /**
+     * Block height corresponding to the most current witness.
+     *
+     * When we first create a CNoteData in CWallet::FindMyNotes, this is set to
+     * -1 as a placeholder. The next time CWallet::ChainTip is called, we can
+     * determine what height the witness cache for this note is valid for (even
+     * if no witnesses were cached), and so can set the correct value in
+     * CWallet::IncrementNoteWitnesses and CWallet::DecrementNoteWitnesses.
+     */
+    int witnessHeight;
+
+CNoteData() : address(), nullifier(), witnessHeight {-1} { }
+CNoteData(libzcash::PaymentAddress a) :
+    address {a}, nullifier(), witnessHeight {-1} { }
+CNoteData(libzcash::PaymentAddress a, uint256 n) :
+    address {a}, nullifier {n}, witnessHeight {-1} { }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+        inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+        READWRITE(address);
+        READWRITE(nullifier);
+        READWRITE(witnesses);
+        READWRITE(witnessHeight);
+    }
+
+    friend bool operator<(const CNoteData& a, const CNoteData& b) {
+        return (a.address < b.address ||
+                (a.address == b.address && a.nullifier < b.nullifier));
+    }
+
+    friend bool operator==(const CNoteData& a, const CNoteData& b) {
+        return (a.address == b.address && a.nullifier == b.nullifier);
+    }
+
+    friend bool operator!=(const CNoteData& a, const CNoteData& b) {
+        return !(a == b);
+    }
+};
+
+typedef std::map<JSOutPoint, CNoteData> mapNoteData_t;
+
+/** Decrypted note and its location in a transaction. */
+struct CNotePlaintextEntry
+{
+    JSOutPoint jsop;
+    libzcash::PaymentAddress address;
+    libzcash::NotePlaintext plaintext;
+};
+
+/** Decrypted note, location in a transaction, and confirmation height. */
+struct CUnspentNotePlaintextEntry {
+    JSOutPoint jsop;
+    libzcash::PaymentAddress address;
+    libzcash::NotePlaintext plaintext;
+    int nHeight;
+};
+
+#endif
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index f1761b0fc..edc9ba5e3 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -18,6 +18,7 @@
 #include <util.h>
 #include <wallet/crypter.h>
 #include <wallet/coinselection.h>
+#include <wallet/joinsplit.h>
 #include <wallet/walletdb.h>
 #include <wallet/rpcwallet.h>
 
diff --git a/src/zcash/Address.hpp b/src/zcash/Address.hpp
index 2dbe10a60..c165c20dd 100644
--- a/src/zcash/Address.hpp
+++ b/src/zcash/Address.hpp
@@ -22,7 +22,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(a_pk);
         READWRITE(pk_enc);
     }
@@ -58,7 +58,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(a_pk);
         READWRITE(sk_enc);
     }
diff --git a/src/zcash/CreateJoinSplit.cpp b/src/zcash/CreateJoinSplit.cpp
index bcf9a218e..0eeb0853c 100644
--- a/src/zcash/CreateJoinSplit.cpp
+++ b/src/zcash/CreateJoinSplit.cpp
@@ -2,9 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "../util.h"
-#include "primitives/transaction.h"
-#include "zcash/JoinSplit.hpp"
+#include <../util.h>
+#include <primitives/joinsplit.h>
+#include <primitives/transaction.h>
+#include <zcash/JoinSplit.hpp>
 
 #include <libsnark/common/profiling.hpp>
 
diff --git a/src/zcash/IncrementalMerkleTree.hpp b/src/zcash/IncrementalMerkleTree.hpp
index 151a395c1..64f79b8dd 100644
--- a/src/zcash/IncrementalMerkleTree.hpp
+++ b/src/zcash/IncrementalMerkleTree.hpp
@@ -20,7 +20,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(authentication_path);
         READWRITE(index);
     }
@@ -90,7 +90,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(left);
         READWRITE(right);
         READWRITE(parents);
@@ -156,7 +156,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(tree);
         READWRITE(filled);
         READWRITE(cursor);
diff --git a/src/zcash/Note.hpp b/src/zcash/Note.hpp
index faacd2720..9b2676931 100644
--- a/src/zcash/Note.hpp
+++ b/src/zcash/Note.hpp
@@ -40,7 +40,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         unsigned char leadingByte = 0x00;
         READWRITE(leadingByte);
 
diff --git a/src/zcash/Proof.hpp b/src/zcash/Proof.hpp
index 5f05aa2c5..573a65cd3 100644
--- a/src/zcash/Proof.hpp
+++ b/src/zcash/Proof.hpp
@@ -25,7 +25,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(data);
     }
 
@@ -58,7 +58,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(data);
     }
 
@@ -93,7 +93,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         unsigned char leadingByte = G1_PREFIX_MASK;
 
         if (y_lsb) {
@@ -143,7 +143,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         unsigned char leadingByte = G2_PREFIX_MASK;
 
         if (y_gt) {
@@ -204,7 +204,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(g_A);
         READWRITE(g_A_prime);
         READWRITE(g_B);
diff --git a/src/zkaddr.cpp b/src/zkaddr.cpp
new file mode 100644
index 000000000..930f37cd7
--- /dev/null
+++ b/src/zkaddr.cpp
@@ -0,0 +1,64 @@
+// Copyright (c) 2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <streams.h>
+#include <zkaddr.h>
+
+template<class DATA_TYPE, CChainParams::Base58Type PREFIX, size_t SER_SIZE>
+bool CZCEncoding<DATA_TYPE, PREFIX, SER_SIZE>::Set(const DATA_TYPE& addr)
+{
+    CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+    ss << addr;
+    std::vector<unsigned char> addrSerialized(ss.begin(), ss.end());
+    assert(addrSerialized.size() == SER_SIZE);
+    SetData(Params().Base58Prefix(PREFIX), &addrSerialized[0], SER_SIZE);
+    return true;
+}
+
+template<class DATA_TYPE, CChainParams::Base58Type PREFIX, size_t SER_SIZE>
+DATA_TYPE CZCEncoding<DATA_TYPE, PREFIX, SER_SIZE>::Get() const
+{
+    if (vchData.size() != SER_SIZE) {
+        throw std::runtime_error(
+            PrependName(" is invalid")
+            );
+    }
+
+    if (vchVersion != Params().Base58Prefix(PREFIX)) {
+        throw std::runtime_error(
+            PrependName(" is for wrong network type")
+            );
+    }
+
+    std::vector<unsigned char> serialized(vchData.begin(), vchData.end());
+
+    CDataStream ss(serialized, SER_NETWORK, PROTOCOL_VERSION);
+    DATA_TYPE ret;
+    ss >> ret;
+    return ret;
+}
+
+// Explicit instantiations for libzcash::PaymentAddress
+template bool CZCEncoding<libzcash::PaymentAddress,
+                          CChainParams::ZCPAYMENT_ADDRRESS,
+                          libzcash::SerializedPaymentAddressSize>::Set(const libzcash::PaymentAddress& addr);
+template libzcash::PaymentAddress CZCEncoding<libzcash::PaymentAddress,
+                                              CChainParams::ZCPAYMENT_ADDRRESS,
+                                              libzcash::SerializedPaymentAddressSize>::Get() const;
+
+// Explicit instantiations for libzcash::ViewingKey
+template bool CZCEncoding<libzcash::ViewingKey,
+                          CChainParams::ZCVIEWING_KEY,
+                          libzcash::SerializedViewingKeySize>::Set(const libzcash::ViewingKey& vk);
+template libzcash::ViewingKey CZCEncoding<libzcash::ViewingKey,
+                                          CChainParams::ZCVIEWING_KEY,
+                                          libzcash::SerializedViewingKeySize>::Get() const;
+
+// Explicit instantiations for libzcash::SpendingKey
+template bool CZCEncoding<libzcash::SpendingKey,
+                          CChainParams::ZCSPENDING_KEY,
+                          libzcash::SerializedSpendingKeySize>::Set(const libzcash::SpendingKey& sk);
+template libzcash::SpendingKey CZCEncoding<libzcash::SpendingKey,
+                                           CChainParams::ZCSPENDING_KEY,
+                                           libzcash::SerializedSpendingKeySize>::Get() const;
diff --git a/src/zkaddr.h b/src/zkaddr.h
new file mode 100644
index 000000000..6546b6b49
--- /dev/null
+++ b/src/zkaddr.h
@@ -0,0 +1,57 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_ZKADDR_H
+#define BITCOIN_ZKADDR_H
+
+#include <base58.h>
+#include <chainparams.h>
+#include <zcash/Address.hpp>
+
+template<class DATA_TYPE, CChainParams::Base58Type PREFIX, size_t SER_SIZE>
+    class CZCEncoding : public CBase58Data {
+protected:
+    virtual std::string PrependName(const std::string& s) const = 0;
+
+public:
+    bool Set(const DATA_TYPE& addr);
+
+    DATA_TYPE Get() const;
+};
+
+class CZCPaymentAddress : public CZCEncoding<libzcash::PaymentAddress, CChainParams::ZCPAYMENT_ADDRRESS, libzcash::SerializedPaymentAddressSize> {
+protected:
+    std::string PrependName(const std::string& s) const { return "payment address" + s; }
+
+public:
+    CZCPaymentAddress() {}
+
+    CZCPaymentAddress(const std::string& strAddress) { SetString(strAddress.c_str(), 2); }
+    CZCPaymentAddress(const libzcash::PaymentAddress& addr) { Set(addr); }
+};
+
+class CZCViewingKey : public CZCEncoding<libzcash::ViewingKey, CChainParams::ZCVIEWING_KEY, libzcash::SerializedViewingKeySize> {
+protected:
+    std::string PrependName(const std::string& s) const { return "viewing key" + s; }
+
+public:
+    CZCViewingKey() {}
+
+    CZCViewingKey(const std::string& strViewingKey) { SetString(strViewingKey.c_str(), 3); }
+    CZCViewingKey(const libzcash::ViewingKey& vk) { Set(vk); }
+};
+
+class CZCSpendingKey : public CZCEncoding<libzcash::SpendingKey, CChainParams::ZCSPENDING_KEY, libzcash::SerializedSpendingKeySize> {
+protected:
+    std::string PrependName(const std::string& s) const { return "spending key" + s; }
+
+public:
+    CZCSpendingKey() {}
+
+    CZCSpendingKey(const std::string& strAddress) { SetString(strAddress.c_str(), 2); }
+    CZCSpendingKey(const libzcash::SpendingKey& addr) { Set(addr); }
+};
+
+#endif