diff --git a/src/Makefile.am b/src/Makefile.am
index aa3213ff6..bca93e6ce 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -107,9 +107,12 @@ LIBZCASH_H = \
   zcash/IncrementalMerkleTree.hpp \
   zcash/NoteEncryption.hpp \
   zcash/Address.hpp \
+  zcash/address/bip44.h \
+  zcash/address/mnemonic.h \
+  zcash/address/orchard.h \
   zcash/address/sapling.hpp \
   zcash/address/sprout.hpp \
-  zcash/address/orchard.h \
+  zcash/address/unified.h \
   zcash/address/zip32.h \
   zcash/History.hpp \
   zcash/JoinSplit.hpp \
@@ -536,9 +539,12 @@ libzcash_a_SOURCES = \
   zcash/IncrementalMerkleTree.cpp \
   zcash/NoteEncryption.cpp \
   zcash/Address.cpp \
+  zcash/address/bip44.cpp \
+  zcash/address/mnemonic.cpp \
+  zcash/address/orchard.cpp \
   zcash/address/sapling.cpp \
   zcash/address/sprout.cpp \
-  zcash/address/orchard.cpp \
+  zcash/address/unified.cpp \
   zcash/address/zip32.cpp \
   zcash/History.cpp \
   zcash/JoinSplit.cpp \
diff --git a/src/gtest/test_keys.cpp b/src/gtest/test_keys.cpp
index 4ff275128..d86c959f6 100644
--- a/src/gtest/test_keys.cpp
+++ b/src/gtest/test_keys.cpp
@@ -78,11 +78,11 @@ namespace libzcash {
             return tfm::format("Sapling(%s)", HexStr(ss.begin(), ss.end()));
         }
 
-        std::string operator()(const P2SHAddress &p2sh) const {
+        std::string operator()(const CScriptID &p2sh) const {
             return tfm::format("P2SH(%s)", p2sh.GetHex());
         }
 
-        std::string operator()(const P2PKHAddress &p2pkh) const {
+        std::string operator()(const CKeyID &p2pkh) const {
             return tfm::format("P2PKH(%s)", p2pkh.GetHex());
         }
 
@@ -140,11 +140,11 @@ TEST(Keys, EncodeAndDecodeUnified)
                 ua.AddReceiver(r);
             }
             if (!test[1].isNull()) {
-                libzcash::P2SHAddress r(ParseHex(test[1].get_str()));
+                CScriptID r(ParseHex(test[1].get_str()));
                 ua.AddReceiver(r);
             }
             if (!test[0].isNull()) {
-                libzcash::P2PKHAddress r(ParseHex(test[0].get_str()));
+                CKeyID r(ParseHex(test[0].get_str()));
                 ua.AddReceiver(r);
             }
 
diff --git a/src/key_io.cpp b/src/key_io.cpp
index db83bea04..e22243f9c 100644
--- a/src/key_io.cpp
+++ b/src/key_io.cpp
@@ -56,8 +56,8 @@ public:
     DataLenForReceiver() {}
 
     size_t operator()(const libzcash::SaplingPaymentAddress &zaddr) const { return 43; }
-    size_t operator()(const libzcash::P2SHAddress &p2sh) const { return 20; }
-    size_t operator()(const libzcash::P2PKHAddress &p2pkh) const { return 20; }
+    size_t operator()(const CScriptID &p2sh) const { return 20; }
+    size_t operator()(const CKeyID &p2pkh) const { return 20; }
     size_t operator()(const libzcash::UnknownReceiver &unknown) const { return unknown.data.size(); }
 };
 
@@ -82,11 +82,11 @@ public:
         memcpy(data, ss.data(), ss.size());
     }
 
-    void operator()(const libzcash::P2SHAddress &p2sh) const {
+    void operator()(const CScriptID &p2sh) const {
         memcpy(data, p2sh.begin(), p2sh.size());
     }
 
-    void operator()(const libzcash::P2PKHAddress &p2pkh) const {
+    void operator()(const CKeyID &p2pkh) const {
         memcpy(data, p2pkh.begin(), p2pkh.size());
     }
 
@@ -421,7 +421,7 @@ static bool AddP2SHReceiver(void* ua, const unsigned char* raw)
         reinterpret_cast<const char*>(raw + 20),
         SER_NETWORK,
         PROTOCOL_VERSION);
-    libzcash::P2SHAddress receiver;
+    CScriptID receiver;
     ss >> receiver;
     return reinterpret_cast<libzcash::UnifiedAddress*>(ua)->AddReceiver(receiver);
 }
@@ -436,7 +436,7 @@ static bool AddP2PKHReceiver(void* ua, const unsigned char* raw)
         reinterpret_cast<const char*>(raw + 20),
         SER_NETWORK,
         PROTOCOL_VERSION);
-    libzcash::P2PKHAddress receiver;
+    CKeyID receiver;
     ss >> receiver;
     return reinterpret_cast<libzcash::UnifiedAddress*>(ua)->AddReceiver(receiver);
 }
diff --git a/src/keystore.h b/src/keystore.h
index 78bf5c400..c2e40b399 100644
--- a/src/keystore.h
+++ b/src/keystore.h
@@ -11,6 +11,7 @@
 #include "script/script.h"
 #include "script/standard.h"
 #include "sync.h"
+#include "zcash/address/mnemonic.h"
 #include "zcash/Address.hpp"
 #include "zcash/NoteEncryption.hpp"
 
diff --git a/src/pubkey.h b/src/pubkey.h
index 4cdfbef38..94ff547c4 100644
--- a/src/pubkey.h
+++ b/src/pubkey.h
@@ -22,6 +22,7 @@ class CKeyID : public uint160
 public:
     CKeyID() : uint160() {}
     CKeyID(const uint160& in) : uint160(in) {}
+    explicit CKeyID(const std::vector<unsigned char>& vch) : uint160(vch) {}
 };
 
 typedef uint256 ChainCode;
diff --git a/src/script/script.h b/src/script/script.h
index e67119197..b20227caf 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -625,6 +625,16 @@ public:
     }
 };
 
+/** A reference to a CScript: the Hash160 of its serialization */
+class CScriptID : public uint160
+{
+public:
+    CScriptID() : uint160() {}
+    explicit CScriptID(const CScript& in);
+    CScriptID(const uint160& in) : uint160(in) {}
+    explicit CScriptID(const std::vector<unsigned char>& vch) : uint160(vch) {}
+};
+
 class CReserveScript
 {
 public:
diff --git a/src/script/standard.h b/src/script/standard.h
index 09a23368f..920ac165d 100644
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -18,15 +18,6 @@ static const bool DEFAULT_ACCEPT_DATACARRIER = true;
 class CKeyID;
 class CScript;
 
-/** A reference to a CScript: the Hash160 of its serialization (see script.h) */
-class CScriptID : public uint160
-{
-public:
-    CScriptID() : uint160() {}
-    explicit CScriptID(const CScript& in);
-    CScriptID(const uint160& in) : uint160(in) {}
-};
-
 /**
  * Default setting for nMaxDatacarrierBytes. 80 bytes of data, +1 for OP_RETURN,
  * +2 for the pushdata opcodes.
diff --git a/src/wallet/gtest/test_orchard_zkeys.cpp b/src/wallet/gtest/test_orchard_zkeys.cpp
index bdf84f66c..3afd22f0a 100644
--- a/src/wallet/gtest/test_orchard_zkeys.cpp
+++ b/src/wallet/gtest/test_orchard_zkeys.cpp
@@ -4,6 +4,7 @@
 
 #include <gtest/gtest.h>
 
+#include "zcash/address/mnemonic.h"
 #include "zcash/address/orchard.hpp"
 
 TEST(OrchardZkeysTest, IVKSerializationRoundtrip) {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 3bb5c55d1..6e1ffa2fa 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -23,6 +23,9 @@
 #include "wallet/crypter.h"
 #include "wallet/walletdb.h"
 #include "wallet/rpcwallet.h"
+#include "zcash/address/bip44.h"
+#include "zcash/address/unified.h"
+#include "zcash/address/mnemonic.h"
 #include "zcash/Address.hpp"
 #include "zcash/Note.hpp"
 #include "base58.h"
diff --git a/src/zcash/Address.cpp b/src/zcash/Address.cpp
index 9b5340cb1..568b3bbff 100644
--- a/src/zcash/Address.cpp
+++ b/src/zcash/Address.cpp
@@ -24,8 +24,8 @@ bool UnifiedAddress::AddReceiver(Receiver receiver) {
         auto t = std::visit(TypecodeForReceiver(), r);
         if (
             (t == typecode) ||
-            (std::holds_alternative<P2PKHAddress>(r) && std::holds_alternative<P2SHAddress>(receiver)) ||
-            (std::holds_alternative<P2SHAddress>(r) && std::holds_alternative<P2PKHAddress>(receiver))
+            (std::holds_alternative<CKeyID>(r) && std::holds_alternative<CScriptID>(receiver)) ||
+            (std::holds_alternative<CScriptID>(r) && std::holds_alternative<CKeyID>(receiver))
         ) {
             return false;
         }
@@ -76,13 +76,13 @@ uint32_t TypecodeForReceiver::operator()(
 }
 
 uint32_t TypecodeForReceiver::operator()(
-    const libzcash::P2SHAddress &p2sh) const
+    const CScriptID &p2sh) const
 {
     return ZCASH_UA_TYPECODE_P2SH;
 }
 
 uint32_t TypecodeForReceiver::operator()(
-    const libzcash::P2PKHAddress &p2sh) const
+    const CKeyID &p2sh) const
 {
     return ZCASH_UA_TYPECODE_P2PKH;
 }
@@ -100,13 +100,13 @@ std::optional<libzcash::RawAddress> ReceiverToRawAddress::operator()(
 }
 
 std::optional<libzcash::RawAddress> ReceiverToRawAddress::operator()(
-    const libzcash::P2SHAddress &p2sh) const
+    const CScriptID &p2sh) const
 {
     return std::nullopt;
 }
 
 std::optional<libzcash::RawAddress> ReceiverToRawAddress::operator()(
-    const libzcash::P2PKHAddress &p2sh) const
+    const CKeyID &p2sh) const
 {
     return std::nullopt;
 }
diff --git a/src/zcash/Address.hpp b/src/zcash/Address.hpp
index e41272a90..09e6144a4 100644
--- a/src/zcash/Address.hpp
+++ b/src/zcash/Address.hpp
@@ -2,6 +2,8 @@
 #define ZC_ADDRESS_H_
 
 #include "uint256.h"
+#include "pubkey.h"
+#include "script/script.h"
 #include "zcash/address/orchard.hpp"
 #include "zcash/address/sapling.hpp"
 #include "zcash/address/sprout.hpp"
@@ -10,17 +12,6 @@
 #include <variant>
 
 namespace libzcash {
-// We use new classes here instead of CKeyID and CScriptID to prevent a cyclic dependency.
-class P2PKHAddress: public uint160 {
-public:
-    P2PKHAddress() {}
-    explicit P2PKHAddress(const std::vector<unsigned char>& vch) : uint160(vch) {}
-};
-class P2SHAddress: public uint160 {
-public:
-    P2SHAddress() {}
-    explicit P2SHAddress(const std::vector<unsigned char>& vch) : uint160(vch) {}
-};
 
 /** Protocol addresses that can receive funds in a transaction. */
 typedef std::variant<SproutPaymentAddress, SaplingPaymentAddress> RawAddress;
@@ -60,8 +51,8 @@ public:
  */
 typedef std::variant<
     SaplingPaymentAddress,
-    P2SHAddress,
-    P2PKHAddress,
+    CScriptID,
+    CKeyID,
     UnknownReceiver> Receiver;
 
 struct ReceiverIterator {
@@ -178,8 +169,8 @@ public:
     TypecodeForReceiver() {}
 
     uint32_t operator()(const libzcash::SaplingPaymentAddress &zaddr) const;
-    uint32_t operator()(const libzcash::P2SHAddress &p2sh) const;
-    uint32_t operator()(const libzcash::P2PKHAddress &p2pkh) const;
+    uint32_t operator()(const CScriptID &p2sh) const;
+    uint32_t operator()(const CKeyID &p2pkh) const;
     uint32_t operator()(const libzcash::UnknownReceiver &p2pkh) const;
 };
 
@@ -191,8 +182,8 @@ public:
     ReceiverToRawAddress() {}
 
     std::optional<libzcash::RawAddress> operator()(const libzcash::SaplingPaymentAddress &zaddr) const;
-    std::optional<libzcash::RawAddress> operator()(const libzcash::P2SHAddress &p2sh) const;
-    std::optional<libzcash::RawAddress> operator()(const libzcash::P2PKHAddress &p2pkh) const;
+    std::optional<libzcash::RawAddress> operator()(const CScriptID &p2sh) const;
+    std::optional<libzcash::RawAddress> operator()(const CKeyID &p2pkh) const;
     std::optional<libzcash::RawAddress> operator()(const libzcash::UnknownReceiver &p2pkh) const;
 };
 
diff --git a/src/zcash/address/bip44.cpp b/src/zcash/address/bip44.cpp
new file mode 100644
index 000000000..f3e8b69e8
--- /dev/null
+++ b/src/zcash/address/bip44.cpp
@@ -0,0 +1,70 @@
+// Copyright (c) 2021 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#include "bip44.h"
+
+std::optional<std::pair<CExtKey, HDKeyPath>> libzcash::DeriveBip44TransparentAccountKey(const HDSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId) {
+    auto rawSeed = seed.RawSeed();
+    auto m = CExtKey::Master(rawSeed.data(), rawSeed.size());
+
+    // We use a fixed keypath scheme of m/44'/coin_type'/account'
+    // Derive m/44'
+    auto m_44h = m.Derive(44 | HARDENED_KEY_LIMIT);
+    if (!m_44h.has_value()) return std::nullopt;
+
+    // Derive m/44'/coin_type'
+    auto m_44h_cth = m_44h.value().Derive(bip44CoinType | HARDENED_KEY_LIMIT);
+    if (!m_44h_cth.has_value()) return std::nullopt;
+
+    // Derive m/44'/coin_type'/account_id'
+    auto result = m_44h_cth.value().Derive(accountId | HARDENED_KEY_LIMIT);
+    if (!result.has_value()) return std::nullopt;
+
+    auto hdKeypath = "m/44'/" + std::to_string(bip44CoinType) + "'/" + std::to_string(accountId) + "'";
+
+    return std::make_pair(result.value(), hdKeypath);
+}
+
+std::optional<libzcash::Bip44AccountChains> libzcash::Bip44AccountChains::ForAccount(
+        const HDSeed& seed,
+        uint32_t bip44CoinType,
+        libzcash::AccountId accountId) {
+    auto accountKeyOpt = DeriveBip44TransparentAccountKey(seed, bip44CoinType, accountId);
+    if (!accountKeyOpt.has_value()) return std::nullopt;
+
+    auto accountKey = accountKeyOpt.value();
+    auto external = accountKey.first.Derive(0);
+    auto internal = accountKey.first.Derive(1);
+
+    if (!(external.has_value() && internal.has_value())) return std::nullopt;
+
+    return Bip44AccountChains(seed.Fingerprint(), bip44CoinType, accountId, external.value(), internal.value());
+}
+
+std::optional<std::pair<CExtKey, HDKeyPath>> libzcash::Bip44AccountChains::DeriveExternal(uint32_t addrIndex) {
+    auto childKey = external.Derive(addrIndex);
+    if (!childKey.has_value()) return std::nullopt;
+
+    auto hdKeypath = "m/44'/"
+        + std::to_string(bip44CoinType) + "'/"
+        + std::to_string(accountId) + "'/"
+        + "0/"
+        + std::to_string(addrIndex);
+
+    return std::make_pair(childKey.value(), hdKeypath);
+}
+
+std::optional<std::pair<CExtKey, HDKeyPath>> libzcash::Bip44AccountChains::DeriveInternal(uint32_t addrIndex) {
+    auto childKey = internal.Derive(addrIndex);
+    if (!childKey.has_value()) return std::nullopt;
+
+    auto hdKeypath = "m/44'/"
+        + std::to_string(bip44CoinType) + "'/"
+        + std::to_string(accountId) + "'/"
+        + "1/"
+        + std::to_string(addrIndex);
+
+    return std::make_pair(childKey.value(), hdKeypath);
+}
+
diff --git a/src/zcash/address/bip44.h b/src/zcash/address/bip44.h
new file mode 100644
index 000000000..4a6bc15c9
--- /dev/null
+++ b/src/zcash/address/bip44.h
@@ -0,0 +1,36 @@
+// Copyright (c) 2021 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#ifndef ZCASH_ZCASH_ADDRESS_BIP44_H
+#define ZCASH_ZCASH_ADDRESS_BIP44_H
+
+#include "zip32.h"
+
+namespace libzcash {
+
+std::optional<std::pair<CExtKey, HDKeyPath>> DeriveBip44TransparentAccountKey(const HDSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId);
+
+class Bip44AccountChains {
+private:
+    uint256 seedFp;
+    libzcash::AccountId accountId;
+    uint32_t bip44CoinType;
+    CExtKey external;
+    CExtKey internal;
+
+    Bip44AccountChains(uint256 seedFpIn, uint32_t bip44CoinTypeIn, libzcash::AccountId accountIdIn, CExtKey externalIn, CExtKey internalIn):
+        seedFp(seedFpIn), accountId(accountIdIn), bip44CoinType(bip44CoinTypeIn), external(externalIn), internal(internalIn) {}
+public:
+    static std::optional<Bip44AccountChains> ForAccount(
+            const HDSeed& mnemonic,
+            uint32_t bip44CoinType,
+            libzcash::AccountId accountId);
+
+    std::optional<std::pair<CExtKey, HDKeyPath>> DeriveExternal(uint32_t addrIndex);
+    std::optional<std::pair<CExtKey, HDKeyPath>> DeriveInternal(uint32_t addrIndex);
+};
+
+} //namespace libzcash
+
+#endif // ZCASH_ZCASH_ADDRESS_BIP44_H
diff --git a/src/zcash/address/mnemonic.cpp b/src/zcash/address/mnemonic.cpp
new file mode 100644
index 000000000..97ac24389
--- /dev/null
+++ b/src/zcash/address/mnemonic.cpp
@@ -0,0 +1,37 @@
+// Copyright (c) 2018-2021 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#include "random.h"
+
+#include "mnemonic.h"
+
+#include "bip44.h"
+#include "unified.h"
+
+using namespace libzcash;
+
+MnemonicSeed MnemonicSeed::Random(uint32_t bip44CoinType, Language language, size_t entropyLen)
+{
+    assert(entropyLen >= 32);
+    while (true) { // loop until we find usable entropy
+        RawHDSeed entropy(entropyLen, 0);
+        GetRandBytes(entropy.data(), entropyLen);
+        const char* phrase = zip339_entropy_to_phrase(language, entropy.data(), entropyLen);
+        SecureString mnemonic(phrase);
+        zip339_free_phrase(phrase);
+        MnemonicSeed seed(language, mnemonic);
+
+        // Verify that the seed data is valid entropy for unified spending keys at
+        // account 0 and at both the public & private chain levels for account 0x7FFFFFFF.
+        // It is not necessary to check for a valid diversified Sapling address at
+        // account 0x7FFFFFFF because derivation via the legacy path can simply search
+        // for a valid diversifier; unlike in the unified spending key case, diversifier
+        // indices don't need to line up with anything.
+        if (ZcashdUnifiedSpendingKey::ForAccount(seed, bip44CoinType, 0).has_value() &&
+            Bip44AccountChains::ForAccount(seed, bip44CoinType, ZCASH_LEGACY_ACCOUNT).has_value())  {
+            return seed;
+        }
+    }
+}
+
diff --git a/src/zcash/address/mnemonic.h b/src/zcash/address/mnemonic.h
new file mode 100644
index 000000000..db9f6a517
--- /dev/null
+++ b/src/zcash/address/mnemonic.h
@@ -0,0 +1,107 @@
+// Copyright (c) 2021 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#ifndef ZCASH_ZCASH_ADDRESS_MNEMONIC_H
+#define ZCASH_ZCASH_ADDRESS_MNEMONIC_H
+
+#include "zip32.h"
+
+class MnemonicSeed: public HDSeed {
+private:
+    Language language;
+    SecureString mnemonic;
+
+    MnemonicSeed() {}
+
+    void SetSeedFromMnemonic() {
+        seed.resize(64);
+        zip339_phrase_to_seed(language, mnemonic.c_str(), (uint8_t (*)[64])seed.data());
+    }
+
+public:
+    MnemonicSeed(Language languageIn, SecureString mnemonicIn): language(languageIn), mnemonic(mnemonicIn) {
+        SetSeedFromMnemonic();
+    }
+
+    /**
+     * Randomly generate a new mnemonic seed. A SLIP-44 coin type is required to make it possible
+     * to check that the generated seed can produce valid transparent and unified addresses at account
+     * numbers 0x7FFFFFFF and 0x00 respectively.
+     */
+    static MnemonicSeed Random(uint32_t bip44CoinType, Language language = English, size_t entropyLen = 32);
+
+    static std::string LanguageName(Language language) {
+        switch (language) {
+            case English:
+                return "English";
+            case SimplifiedChinese:
+                return "Simplified Chinese";
+            case TraditionalChinese:
+                return "Traditional Chinese";
+            case Czech:
+                return "Czech";
+            case French:
+                return "French";
+            case Italian:
+                return "Italian";
+            case Japanese:
+                return "Japanese";
+            case Korean:
+                return "Korean";
+            case Portuguese:
+                return "Portuguese";
+            case Spanish:
+                return "Spanish";
+            default:
+                return "INVALID";
+        }
+    }
+
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        if (ser_action.ForRead()) {
+            uint32_t language0;
+
+            READWRITE(language0);
+            READWRITE(mnemonic);
+            language = (Language) language0;
+            SetSeedFromMnemonic();
+        } else {
+            uint32_t language0 = (uint32_t) language;
+
+            READWRITE(language0);
+            READWRITE(mnemonic);
+        }
+   }
+
+    template <typename Stream>
+    static MnemonicSeed Read(Stream& stream) {
+        MnemonicSeed seed;
+        stream >> seed;
+        return seed;
+    }
+
+    const Language GetLanguage() const {
+        return language;
+    }
+
+    const SecureString& GetMnemonic() const {
+        return mnemonic;
+    }
+
+    friend bool operator==(const MnemonicSeed& a, const MnemonicSeed& b)
+    {
+        return a.seed == b.seed;
+    }
+
+    friend bool operator!=(const MnemonicSeed& a, const MnemonicSeed& b)
+    {
+        return !(a == b);
+    }
+};
+
+#endif // ZCASH_ZCASH_ADDRESS_MNEMONIC_H
+
diff --git a/src/zcash/address/unified.cpp b/src/zcash/address/unified.cpp
new file mode 100644
index 000000000..d72a8686e
--- /dev/null
+++ b/src/zcash/address/unified.cpp
@@ -0,0 +1,73 @@
+// Copyright (c) 2021 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#include "unified.h"
+#include "bip44.h"
+
+using namespace libzcash;
+
+//
+// Unified Keys
+//
+
+std::optional<std::pair<ZcashdUnifiedSpendingKey, HDKeyPath>> ZcashdUnifiedSpendingKey::ForAccount(const HDSeed& seed, uint32_t bip44CoinType, AccountId accountId) {
+    ZcashdUnifiedSpendingKey usk;
+    usk.accountId = accountId;
+
+    auto transparentKey = DeriveBip44TransparentAccountKey(seed, bip44CoinType, accountId);
+    if (!transparentKey.has_value()) return std::nullopt;
+    usk.transparentKey = transparentKey.value().first;
+
+    auto saplingKey = SaplingExtendedSpendingKey::ForAccount(seed, bip44CoinType, accountId);
+    usk.saplingKey = saplingKey.first;
+
+    return std::make_pair(usk, saplingKey.second);
+}
+
+ZcashdUnifiedFullViewingKey ZcashdUnifiedSpendingKey::ToFullViewingKey() const {
+    ZcashdUnifiedFullViewingKey ufvk;
+
+    if (transparentKey.has_value()) {
+        ufvk.transparentKey = transparentKey.value().Neuter();
+    }
+
+    if (saplingKey.has_value()) {
+        ufvk.saplingKey = saplingKey.value().ToXFVK();
+    }
+
+    return ufvk;
+}
+
+std::optional<UnifiedAddress> ZcashdUnifiedFullViewingKey::Address(diversifier_index_t j) const {
+    UnifiedAddress ua;
+
+    if (saplingKey.has_value()) {
+        auto saplingAddress = saplingKey.value().Address(j);
+        if (saplingAddress.has_value()) {
+            ua.AddReceiver(saplingAddress.value());
+        } else {
+            return std::nullopt;
+        }
+    }
+
+    if (transparentKey.has_value()) {
+        auto childIndex = j.ToTransparentChildIndex();
+        if (!childIndex.has_value()) return std::nullopt;
+
+        CExtPubKey externalKey;
+        if (!transparentKey.value().Derive(externalKey, 0)) {
+            return std::nullopt;
+        }
+
+        CExtPubKey childKey;
+        if (externalKey.Derive(childKey, childIndex.value())) {
+            ua.AddReceiver(childKey.pubkey.GetID());
+        } else {
+            return std::nullopt;
+        }
+    }
+
+    return ua;
+}
+
diff --git a/src/zcash/address/unified.h b/src/zcash/address/unified.h
new file mode 100644
index 000000000..be87a8d6b
--- /dev/null
+++ b/src/zcash/address/unified.h
@@ -0,0 +1,74 @@
+// Copyright (c) 2021 The Zcash developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+#ifndef ZCASH_ZCASH_ADDRESS_UNIFIED_H
+#define ZCASH_ZCASH_ADDRESS_UNIFIED_H
+
+#include "zip32.h"
+#include "bip44.h"
+#include "zcash/Address.hpp"
+
+namespace libzcash {
+
+class ZcashdUnifiedSpendingKey;
+class ZcashdUnifiedFullViewingKey;
+
+class ZcashdUnifiedFullViewingKey {
+private:
+    std::optional<CExtPubKey> transparentKey;
+    std::optional<SaplingExtendedFullViewingKey> saplingKey;
+
+    ZcashdUnifiedFullViewingKey() {}
+
+    friend class ZcashdUnifiedSpendingKey;
+public:
+    const std::optional<CExtPubKey>& GetTransparentKey() const {
+        return transparentKey;
+    }
+
+    const std::optional<SaplingExtendedFullViewingKey>& GetSaplingExtendedFullViewingKey() const {
+        return saplingKey;
+    }
+
+    std::optional<UnifiedAddress> Address(diversifier_index_t j) const;
+
+    std::pair<UnifiedAddress, diversifier_index_t> FindAddress(diversifier_index_t j) const {
+        auto addr = Address(j);
+        while (!addr.has_value()) {
+            if (!j.increment())
+                throw std::runtime_error(std::string(__func__) + ": diversifier index overflow.");;
+            addr = Address(j);
+        }
+        return std::make_pair(addr.value(), j);
+    }
+};
+
+class ZcashdUnifiedSpendingKey {
+private:
+    libzcash::AccountId accountId;
+    std::optional<CExtKey> transparentKey;
+    std::optional<SaplingExtendedSpendingKey> saplingKey;
+
+    ZcashdUnifiedSpendingKey() {}
+public:
+    static std::optional<std::pair<ZcashdUnifiedSpendingKey, HDKeyPath>> ForAccount(
+            const HDSeed& seed,
+            uint32_t bip44CoinType,
+            libzcash::AccountId accountId);
+
+    const std::optional<CExtKey>& GetTransparentKey() const {
+        return transparentKey;
+    }
+
+    const std::optional<SaplingExtendedSpendingKey>& GetSaplingExtendedSpendingKey() const {
+        return saplingKey;
+    }
+
+    ZcashdUnifiedFullViewingKey ToFullViewingKey() const;
+};
+
+} //namespace libzcash
+
+#endif // ZCASH_ZCASH_ADDRESS_UNIFIED_H
+
diff --git a/src/zcash/address/zip32.cpp b/src/zcash/address/zip32.cpp
index f88311fde..fc558edef 100644
--- a/src/zcash/address/zip32.cpp
+++ b/src/zcash/address/zip32.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2018 The Zcash developers
+// Copyright (c) 2018-2021 The Zcash developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or https://www.opensource.org/licenses/mit-license.php .
 
@@ -21,30 +21,6 @@ const unsigned char ZCASH_TADDR_OVK_PERSONAL[BLAKE2bPersonalBytes] =
 
 const libzcash::diversifier_index_t MAX_TRANSPARENT_CHILD_IDX(0x7FFFFFFF);
 
-MnemonicSeed MnemonicSeed::Random(uint32_t bip44CoinType, Language language, size_t entropyLen)
-{
-    assert(entropyLen >= 32);
-    while (true) { // loop until we find usable entropy
-        RawHDSeed entropy(entropyLen, 0);
-        GetRandBytes(entropy.data(), entropyLen);
-        const char* phrase = zip339_entropy_to_phrase(language, entropy.data(), entropyLen);
-        SecureString mnemonic(phrase);
-        zip339_free_phrase(phrase);
-        MnemonicSeed seed(language, mnemonic);
-
-        // Verify that the seed data is valid entropy for unified spending keys at
-        // account 0 and at both the public & private chain levels for account 0x7FFFFFFF.
-        // It is not necessary to check for a valid diversified Sapling address at
-        // account 0x7FFFFFFF because derivation via the legacy path can simply search
-        // for a valid diversifier; unlike in the unified spending key case, diversifier
-        // indices don't need to line up with anything.
-        if (libzcash::ZcashdUnifiedSpendingKey::ForAccount(seed, bip44CoinType, 0).has_value() &&
-            libzcash::Bip44AccountChains::ForAccount(seed, bip44CoinType, ZCASH_LEGACY_ACCOUNT).has_value())  {
-            return seed;
-        }
-    }
-}
-
 uint256 HDSeed::Fingerprint() const
 {
     CBLAKE2bWriter h(SER_GETHASH, 0, ZCASH_HD_SEED_FP_PERSONAL);
@@ -81,74 +57,6 @@ std::optional<unsigned int> diversifier_index_t::ToTransparentChildIndex() const
     }
 }
 
-//
-// Transparent
-//
-
-std::optional<std::pair<CExtKey, HDKeyPath>> DeriveBip44TransparentAccountKey(const MnemonicSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId) {
-    auto rawSeed = seed.RawSeed();
-    auto m = CExtKey::Master(rawSeed.data(), rawSeed.size());
-
-    // We use a fixed keypath scheme of m/44'/coin_type'/account'
-    // Derive m/44'
-    auto m_44h = m.Derive(44 | HARDENED_KEY_LIMIT);
-    if (!m_44h.has_value()) return std::nullopt;
-
-    // Derive m/44'/coin_type'
-    auto m_44h_cth = m_44h.value().Derive(bip44CoinType | HARDENED_KEY_LIMIT);
-    if (!m_44h_cth.has_value()) return std::nullopt;
-
-    // Derive m/44'/coin_type'/account_id'
-    auto result = m_44h_cth.value().Derive(accountId | HARDENED_KEY_LIMIT);
-    if (!result.has_value()) return std::nullopt;
-
-    auto hdKeypath = "m/44'/" + std::to_string(bip44CoinType) + "'/" + std::to_string(accountId) + "'";
-
-    return std::make_pair(result.value(), hdKeypath);
-}
-
-std::optional<Bip44AccountChains> Bip44AccountChains::ForAccount(
-        const MnemonicSeed& seed,
-        uint32_t bip44CoinType,
-        libzcash::AccountId accountId) {
-    auto accountKeyOpt = DeriveBip44TransparentAccountKey(seed, bip44CoinType, accountId);
-    if (!accountKeyOpt.has_value()) return std::nullopt;
-
-    auto accountKey = accountKeyOpt.value();
-    auto external = accountKey.first.Derive(0);
-    auto internal = accountKey.first.Derive(1);
-
-    if (!(external.has_value() && internal.has_value())) return std::nullopt;
-
-    return Bip44AccountChains(seed.Fingerprint(), bip44CoinType, accountId, external.value(), internal.value());
-}
-
-std::optional<std::pair<CExtKey, HDKeyPath>> Bip44AccountChains::DeriveExternal(uint32_t addrIndex) {
-    auto childKey = external.Derive(addrIndex);
-    if (!childKey.has_value()) return std::nullopt;
-
-    auto hdKeypath = "m/44'/"
-        + std::to_string(bip44CoinType) + "'/"
-        + std::to_string(accountId) + "'/"
-        + "0/"
-        + std::to_string(addrIndex);
-
-    return std::make_pair(childKey.value(), hdKeypath);
-}
-
-std::optional<std::pair<CExtKey, HDKeyPath>> Bip44AccountChains::DeriveInternal(uint32_t addrIndex) {
-    auto childKey = internal.Derive(addrIndex);
-    if (!childKey.has_value()) return std::nullopt;
-
-    auto hdKeypath = "m/44'/"
-        + std::to_string(bip44CoinType) + "'/"
-        + std::to_string(accountId) + "'/"
-        + "1/"
-        + std::to_string(addrIndex);
-
-    return std::make_pair(childKey.value(), hdKeypath);
-}
-
 //
 // Sapling
 //
@@ -251,7 +159,7 @@ SaplingExtendedSpendingKey SaplingExtendedSpendingKey::Derive(uint32_t i) const
     return xsk_i;
 }
 
-std::pair<SaplingExtendedSpendingKey, HDKeyPath> SaplingExtendedSpendingKey::ForAccount(const MnemonicSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId) {
+std::pair<SaplingExtendedSpendingKey, HDKeyPath> SaplingExtendedSpendingKey::ForAccount(const HDSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId) {
     auto m = Master(seed);
 
     // We use a fixed keypath scheme of m/32'/coin_type'/account'
@@ -269,7 +177,7 @@ std::pair<SaplingExtendedSpendingKey, HDKeyPath> SaplingExtendedSpendingKey::For
     return std::make_pair(xsk, hdKeypath);
 }
 
-std::pair<SaplingExtendedSpendingKey, HDKeyPath> SaplingExtendedSpendingKey::Legacy(const MnemonicSeed& seed, uint32_t bip44CoinType, uint32_t addressIndex) {
+std::pair<SaplingExtendedSpendingKey, HDKeyPath> SaplingExtendedSpendingKey::Legacy(const HDSeed& seed, uint32_t bip44CoinType, uint32_t addressIndex) {
     auto m = Master(seed);
 
     // We use a fixed keypath scheme of m/32'/coin_type'/0x7FFFFFFF'/addressIndex'
@@ -309,70 +217,6 @@ SaplingExtendedFullViewingKey SaplingExtendedSpendingKey::ToXFVK() const
     return ret;
 }
 
-//
-// Unified
-//
-
-std::optional<std::pair<ZcashdUnifiedSpendingKey, HDKeyPath>> ZcashdUnifiedSpendingKey::ForAccount(const MnemonicSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId) {
-    ZcashdUnifiedSpendingKey usk;
-    usk.accountId = accountId;
-
-    auto transparentKey = DeriveBip44TransparentAccountKey(seed, bip44CoinType, accountId);
-    if (!transparentKey.has_value()) return std::nullopt;
-    usk.transparentKey = transparentKey.value().first;
-
-    auto saplingKey = SaplingExtendedSpendingKey::ForAccount(seed, bip44CoinType, accountId);
-    usk.saplingKey = saplingKey.first;
-
-    return std::make_pair(usk, saplingKey.second);
-}
-
-ZcashdUnifiedFullViewingKey ZcashdUnifiedSpendingKey::ToFullViewingKey() const {
-    ZcashdUnifiedFullViewingKey ufvk;
-
-    if (transparentKey.has_value()) {
-        ufvk.transparentKey = transparentKey.value().Neuter();
-    }
-
-    if (saplingKey.has_value()) {
-        ufvk.saplingKey = saplingKey.value().ToXFVK();
-    }
-
-    return ufvk;
-}
-
-std::optional<ZcashdUnifiedAddress> ZcashdUnifiedFullViewingKey::Address(diversifier_index_t j) const {
-    ZcashdUnifiedAddress ua;
-
-    if (transparentKey.has_value()) {
-        auto childIndex = j.ToTransparentChildIndex();
-        if (!childIndex.has_value()) return std::nullopt;
-
-        CExtPubKey externalKey;
-        if (!transparentKey.value().Derive(externalKey, 0)) {
-            return std::nullopt;
-        }
-
-        CExtPubKey childKey;
-        if (externalKey.Derive(childKey, childIndex.value())) {
-            ua.transparentAddress = childKey.pubkey.GetID();
-        } else {
-            return std::nullopt;
-        }
-    }
-
-    if (saplingKey.has_value()) {
-        auto saplingAddress = saplingKey.value().Address(j);
-        if (saplingAddress.has_value()) {
-            ua.saplingAddress = saplingAddress.value();
-        } else {
-            return std::nullopt;
-        }
-    }
-
-    return ua;
-}
-
 std::optional<unsigned long> ParseHDKeypathAccount(uint32_t purpose, uint32_t coinType, const std::string& keyPath) {
     std::regex pattern("m/" + std::to_string(purpose)  + "'/" + std::to_string(coinType) + "'/([0-9]+)'.*");
     std::smatch matches;
diff --git a/src/zcash/address/zip32.h b/src/zcash/address/zip32.h
index 9da16b71e..7f9cf4cc9 100644
--- a/src/zcash/address/zip32.h
+++ b/src/zcash/address/zip32.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2018 The Zcash developers
+// Copyright (c) 2018-2021 The Zcash developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or https://www.opensource.org/licenses/mit-license.php .
 
@@ -22,13 +22,6 @@ const uint32_t HARDENED_KEY_LIMIT = 0x80000000;
 const size_t ZIP32_XFVK_SIZE = 169;
 const size_t ZIP32_XSK_SIZE = 169;
 
-/**
- * The account identifier used for HD derivation of
- * transparent and Sapling addresses via the legacy
- * `getnewaddress` and `z_getnewaddress` code paths,
- */
-const uint32_t ZCASH_LEGACY_ACCOUNT = HARDENED_KEY_LIMIT - 1;
-
 typedef std::vector<unsigned char, secure_allocator<unsigned char>> RawHDSeed;
 
 typedef std::string HDKeyPath;
@@ -64,102 +57,6 @@ public:
 };
 
 
-class MnemonicSeed: public HDSeed {
-private:
-    Language language;
-    SecureString mnemonic;
-
-    MnemonicSeed() {}
-
-    void SetSeedFromMnemonic() {
-        seed.resize(64);
-        zip339_phrase_to_seed(language, mnemonic.c_str(), (uint8_t (*)[64])seed.data());
-    }
-
-public:
-    MnemonicSeed(Language languageIn, SecureString mnemonicIn): language(languageIn), mnemonic(mnemonicIn) {
-        SetSeedFromMnemonic();
-    }
-
-    /**
-     * Randomly generate a new mnemonic seed. A SLIP-44 coin type is required to make it possible
-     * to check that the generated seed can produce valid transparent and unified addresses at account
-     * numbers 0x7FFFFFFF and 0x00 respectively.
-     */
-    static MnemonicSeed Random(uint32_t bip44CoinType, Language language = English, size_t entropyLen = 32);
-
-    static std::string LanguageName(Language language) {
-        switch (language) {
-            case English:
-                return "English";
-            case SimplifiedChinese:
-                return "Simplified Chinese";
-            case TraditionalChinese:
-                return "Traditional Chinese";
-            case Czech:
-                return "Czech";
-            case French:
-                return "French";
-            case Italian:
-                return "Italian";
-            case Japanese:
-                return "Japanese";
-            case Korean:
-                return "Korean";
-            case Portuguese:
-                return "Portuguese";
-            case Spanish:
-                return "Spanish";
-            default:
-                return "INVALID";
-        }
-    }
-
-    ADD_SERIALIZE_METHODS;
-
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action) {
-        if (ser_action.ForRead()) {
-            uint32_t language0;
-
-            READWRITE(language0);
-            READWRITE(mnemonic);
-            language = (Language) language0;
-            SetSeedFromMnemonic();
-        } else {
-            uint32_t language0 = (uint32_t) language;
-
-            READWRITE(language0);
-            READWRITE(mnemonic);
-        }
-   }
-
-    template <typename Stream>
-    static MnemonicSeed Read(Stream& stream) {
-        MnemonicSeed seed;
-        stream >> seed;
-        return seed;
-    }
-
-    const Language GetLanguage() const {
-        return language;
-    }
-
-    const SecureString& GetMnemonic() const {
-        return mnemonic;
-    }
-
-    friend bool operator==(const MnemonicSeed& a, const MnemonicSeed& b)
-    {
-        return a.seed == b.seed;
-    }
-
-    friend bool operator!=(const MnemonicSeed& a, const MnemonicSeed& b)
-    {
-        return !(a == b);
-    }
-};
-
 // This is not part of ZIP 32, but is here because it's linked to the HD seed.
 uint256 ovkForShieldingFromTaddr(HDSeed& seed);
 
@@ -167,6 +64,13 @@ namespace libzcash {
 
 typedef uint32_t AccountId;
 
+/**
+ * The account identifier used for HD derivation of
+ * transparent and Sapling addresses via the legacy
+ * `getnewaddress` and `z_getnewaddress` code paths,
+ */
+const AccountId ZCASH_LEGACY_ACCOUNT = HARDENED_KEY_LIMIT - 1;
+
 /**
  * 88-bit diversifier index. This would ideally derive from base_uint
  * but those values must have bit widths that are multiples of 32.
@@ -292,8 +196,8 @@ struct SaplingExtendedSpendingKey {
     }
 
     static SaplingExtendedSpendingKey Master(const HDSeed& seed);
-    static std::pair<SaplingExtendedSpendingKey, HDKeyPath> ForAccount(const MnemonicSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId);
-    static std::pair<SaplingExtendedSpendingKey, HDKeyPath> Legacy(const MnemonicSeed& seed, uint32_t bip44CoinType, uint32_t addressIndex);
+    static std::pair<SaplingExtendedSpendingKey, HDKeyPath> ForAccount(const HDSeed& seed, uint32_t bip44CoinType, libzcash::AccountId accountId);
+    static std::pair<SaplingExtendedSpendingKey, HDKeyPath> Legacy(const HDSeed& seed, uint32_t bip44CoinType, uint32_t addressIndex);
 
 
     SaplingExtendedSpendingKey Derive(uint32_t i) const;
@@ -311,104 +215,8 @@ struct SaplingExtendedSpendingKey {
     }
 };
 
-class ZcashdUnifiedSpendingKey;
-class ZcashdUnifiedFullViewingKey;
-
-class ZcashdUnifiedAddress {
-private:
-    diversifier_index_t diversifier_index;
-    std::optional<CKeyID> transparentAddress;
-    std::optional<SaplingPaymentAddress> saplingAddress;
-
-    friend class ZcashdUnifiedFullViewingKey;
-
-    ZcashdUnifiedAddress() {}
-public:
-    const std::optional<CKeyID>& GetTransparentAddress() const {
-        return transparentAddress;
-    }
-
-    const std::optional<SaplingPaymentAddress>& GetSaplingPaymentAddress() const {
-        return saplingAddress;
-    }
-};
-
-class ZcashdUnifiedFullViewingKey {
-private:
-    std::optional<CExtPubKey> transparentKey;
-    std::optional<SaplingExtendedFullViewingKey> saplingKey;
-
-    ZcashdUnifiedFullViewingKey() {}
-
-    friend class ZcashdUnifiedSpendingKey;
-public:
-    const std::optional<CExtPubKey>& GetTransparentKey() const {
-        return transparentKey;
-    }
-
-    const std::optional<SaplingExtendedFullViewingKey>& GetSaplingExtendedFullViewingKey() const {
-        return saplingKey;
-    }
-
-    std::optional<ZcashdUnifiedAddress> Address(diversifier_index_t j) const;
-
-    std::pair<ZcashdUnifiedAddress, diversifier_index_t> FindAddress(diversifier_index_t j) const {
-        auto addr = Address(j);
-        while (!addr.has_value()) {
-            if (!j.increment())
-                throw std::runtime_error(std::string(__func__) + ": diversifier index overflow.");;
-            addr = Address(j);
-        }
-        return std::make_pair(addr.value(), j);
-    }
-};
-
-class ZcashdUnifiedSpendingKey {
-private:
-    libzcash::AccountId accountId;
-    std::optional<CExtKey> transparentKey;
-    std::optional<SaplingExtendedSpendingKey> saplingKey;
-
-    ZcashdUnifiedSpendingKey() {}
-public:
-    static std::optional<std::pair<ZcashdUnifiedSpendingKey, HDKeyPath>> ForAccount(
-            const MnemonicSeed& mnemonic,
-            uint32_t bip44CoinType,
-            libzcash::AccountId accountId);
-
-    const std::optional<CExtKey>& GetTransparentKey() const {
-        return transparentKey;
-    }
-
-    const std::optional<SaplingExtendedSpendingKey>& GetSaplingExtendedSpendingKey() const {
-        return saplingKey;
-    }
-
-    ZcashdUnifiedFullViewingKey ToFullViewingKey() const;
-};
-
 std::optional<unsigned long> ParseHDKeypathAccount(uint32_t purpose, uint32_t coinType, const std::string& keyPath);
 
-class Bip44AccountChains {
-private:
-    uint256 seedFp;
-    libzcash::AccountId accountId;
-    uint32_t bip44CoinType;
-    CExtKey external;
-    CExtKey internal;
-
-    Bip44AccountChains(uint256 seedFpIn, uint32_t bip44CoinTypeIn, libzcash::AccountId accountIdIn, CExtKey externalIn, CExtKey internalIn):
-        seedFp(seedFpIn), accountId(accountIdIn), bip44CoinType(bip44CoinTypeIn), external(externalIn), internal(internalIn) {}
-public:
-    static std::optional<Bip44AccountChains> ForAccount(
-            const MnemonicSeed& mnemonic,
-            uint32_t bip44CoinType,
-            libzcash::AccountId accountId);
-
-    std::optional<std::pair<CExtKey, HDKeyPath>> DeriveExternal(uint32_t addrIndex);
-    std::optional<std::pair<CExtKey, HDKeyPath>> DeriveInternal(uint32_t addrIndex);
-};
-
-}
+} //namespace libzcash
 
 #endif // ZCASH_ZCASH_ADDRESS_ZIP32_H