diff --git a/core/src/apps/bitcoin/sign_tx/bitcoin.py b/core/src/apps/bitcoin/sign_tx/bitcoin.py
index 0defbf841..b94d64979 100644
--- a/core/src/apps/bitcoin/sign_tx/bitcoin.py
+++ b/core/src/apps/bitcoin/sign_tx/bitcoin.py
@@ -15,6 +15,7 @@ from ..common import BIP32_WALLET_DEPTH, SIGHASH_ALL, ecdsa_sign
 from ..ownership import verify_nonownership
 from ..verification import SignatureVerifier
 from . import approvers, helpers, progress
+from .hash143 import Hash143
 from .matchcheck import MultisigFingerprintChecker, WalletPathChecker
 
 if False:
@@ -114,19 +115,22 @@ class Bitcoin:
         self.h_inputs = None  # type: Optional[bytes]
 
         # BIP-0143 transaction hashing
-        self.init_hash143()
+        self.hash143 = self.create_hash143()
 
         progress.init(self.tx.inputs_count, self.tx.outputs_count)
 
     def create_hash_writer(self) -> HashWriter:
         return HashWriter(sha256())
 
+    def create_hash143(self) -> Hash143:
+        return Hash143()
+
     async def step1_process_inputs(self) -> None:
         for i in range(self.tx.inputs_count):
             # STAGE_REQUEST_1_INPUT in legacy
             txi = await helpers.request_tx_input(self.tx_req, i, self.coin)
 
-            self.hash143_add_input(txi)  # all inputs are included (non-segwit as well)
+            self.hash143.add_input(txi)  # all inputs are included (non-segwit as well)
             writers.write_tx_input_check(self.h_approved, txi)
 
             if input_is_segwit(txi):
@@ -229,7 +233,7 @@ class Bitcoin:
             await self.approver.add_external_output(txo, script_pubkey)
 
         self.write_tx_output(self.h_approved, txo, script_pubkey)
-        self.hash143_add_output(txo, script_pubkey)
+        self.hash143.add_output(txo, script_pubkey)
 
     async def get_tx_digest(
         self,
@@ -240,7 +244,14 @@ class Bitcoin:
         script_pubkey: bytes,
     ) -> bytes:
         if txi.witness:
-            return self.hash143_preimage_hash(txi, public_keys, threshold)
+            return self.hash143.preimage_hash(
+                txi,
+                public_keys,
+                threshold,
+                self.tx,
+                self.coin,
+                self.get_sighash_type(txi),
+            )
         else:
             digest, _, _ = await self.get_legacy_tx_digest(i, script_pubkey)
             return digest
@@ -304,7 +315,9 @@ class Bitcoin:
         else:
             public_keys = [public_key]
             threshold = 1
-        hash143_hash = self.hash143_preimage_hash(txi, public_keys, threshold)
+        hash143_hash = self.hash143.preimage_hash(
+            txi, public_keys, threshold, self.tx, self.coin, self.get_sighash_type(txi)
+        )
 
         signature = ecdsa_sign(node, hash143_hash)
 
@@ -478,16 +491,16 @@ class Bitcoin:
         # the fork ID value.
         return self.get_sighash_type(txi) & 0xFF
 
+    @staticmethod
     def write_tx_input(
-        self,
         w: writers.Writer,
         txi: Union[TxInput, PrevInput],
         script: bytes,
     ) -> None:
         writers.write_tx_input(w, txi, script)
 
+    @staticmethod
     def write_tx_output(
-        self,
         w: writers.Writer,
         txo: Union[TxOutput, PrevOutput],
         script_pubkey: bytes,
@@ -574,74 +587,6 @@ class Bitcoin:
             signature,
         )
 
-    # BIP-0143
-    # ===
-
-    def init_hash143(self) -> None:
-        self.h_prevouts = HashWriter(sha256())
-        self.h_sequence = HashWriter(sha256())
-        self.h_outputs = HashWriter(sha256())
-
-    def hash143_add_input(self, txi: TxInput) -> None:
-        writers.write_bytes_reversed(
-            self.h_prevouts, txi.prev_hash, writers.TX_HASH_SIZE
-        )
-        writers.write_uint32(self.h_prevouts, txi.prev_index)
-        writers.write_uint32(self.h_sequence, txi.sequence)
-
-    def hash143_add_output(self, txo: TxOutput, script_pubkey: bytes) -> None:
-        writers.write_tx_output(self.h_outputs, txo, script_pubkey)
-
-    def hash143_preimage_hash(
-        self, txi: TxInput, public_keys: List[bytes], threshold: int
-    ) -> bytes:
-        h_preimage = HashWriter(sha256())
-
-        # nVersion
-        writers.write_uint32(h_preimage, self.tx.version)
-
-        # hashPrevouts
-        prevouts_hash = writers.get_tx_hash(
-            self.h_prevouts, double=self.coin.sign_hash_double
-        )
-        writers.write_bytes_fixed(h_preimage, prevouts_hash, writers.TX_HASH_SIZE)
-
-        # hashSequence
-        sequence_hash = writers.get_tx_hash(
-            self.h_sequence, double=self.coin.sign_hash_double
-        )
-        writers.write_bytes_fixed(h_preimage, sequence_hash, writers.TX_HASH_SIZE)
-
-        # outpoint
-        writers.write_bytes_reversed(h_preimage, txi.prev_hash, writers.TX_HASH_SIZE)
-        writers.write_uint32(h_preimage, txi.prev_index)
-
-        # scriptCode
-        script_code = scripts.bip143_derive_script_code(
-            txi, public_keys, threshold, self.coin
-        )
-        writers.write_bytes_prefixed(h_preimage, script_code)
-
-        # amount
-        writers.write_uint64(h_preimage, txi.amount)
-
-        # nSequence
-        writers.write_uint32(h_preimage, txi.sequence)
-
-        # hashOutputs
-        outputs_hash = writers.get_tx_hash(
-            self.h_outputs, double=self.coin.sign_hash_double
-        )
-        writers.write_bytes_fixed(h_preimage, outputs_hash, writers.TX_HASH_SIZE)
-
-        # nLockTime
-        writers.write_uint32(h_preimage, self.tx.lock_time)
-
-        # nHashType
-        writers.write_uint32(h_preimage, self.get_sighash_type(txi))
-
-        return writers.get_tx_hash(h_preimage, double=self.coin.sign_hash_double)
-
 
 def input_is_segwit(txi: TxInput) -> bool:
     return txi.script_type in common.SEGWIT_INPUT_SCRIPT_TYPES or (
diff --git a/core/src/apps/bitcoin/sign_tx/bitcoinlike.py b/core/src/apps/bitcoin/sign_tx/bitcoinlike.py
index 472d4b5b3..2cc0bd2b9 100644
--- a/core/src/apps/bitcoin/sign_tx/bitcoinlike.py
+++ b/core/src/apps/bitcoin/sign_tx/bitcoinlike.py
@@ -49,7 +49,14 @@ class Bitcoinlike(Bitcoin):
         script_pubkey: bytes,
     ) -> bytes:
         if self.coin.force_bip143:
-            return self.hash143_preimage_hash(txi, public_keys, threshold)
+            return self.hash143.preimage_hash(
+                txi,
+                public_keys,
+                threshold,
+                self.tx,
+                self.coin,
+                self.get_sighash_type(txi),
+            )
         else:
             return await super().get_tx_digest(
                 i, txi, public_keys, threshold, script_pubkey
diff --git a/core/src/apps/bitcoin/sign_tx/decred.py b/core/src/apps/bitcoin/sign_tx/decred.py
index aed98829e..d2481e1b2 100644
--- a/core/src/apps/bitcoin/sign_tx/decred.py
+++ b/core/src/apps/bitcoin/sign_tx/decred.py
@@ -12,6 +12,7 @@ from .. import multisig, scripts, writers
 from ..common import ecdsa_hash_pubkey, ecdsa_sign
 from . import approvers, helpers, progress
 from .bitcoin import Bitcoin
+from .hash143 import Hash143
 
 DECRED_SERIALIZE_FULL = const(0 << 16)
 DECRED_SERIALIZE_NO_WITNESS = const(1 << 16)
@@ -33,6 +34,17 @@ if False:
     from apps.common.keychain import Keychain
 
 
+class DecredHash(Hash143):
+    def __init__(self, h_prefix: HashWriter) -> None:
+        self.h_prefix = h_prefix
+
+    def add_input(self, txi: TxInput) -> None:
+        Decred.write_tx_input(self.h_prefix, txi, bytes())
+
+    def add_output(self, txo: TxOutput, script_pubkey: bytes) -> None:
+        Decred.write_tx_output(self.h_prefix, txo, script_pubkey)
+
+
 class Decred(Bitcoin):
     def __init__(
         self,
@@ -42,21 +54,22 @@ class Decred(Bitcoin):
         approver: approvers.Approver,
     ) -> None:
         ensure(coin.decred)
+
+        self.h_prefix = HashWriter(blake256())
+        writers.write_uint32(self.h_prefix, tx.version | DECRED_SERIALIZE_NO_WITNESS)
+        write_bitcoin_varint(self.h_prefix, tx.inputs_count)
+
         super().__init__(tx, keychain, coin, approver)
 
         self.write_tx_header(self.serialized_tx, self.tx, witness_marker=True)
         write_bitcoin_varint(self.serialized_tx, self.tx.inputs_count)
 
-    def init_hash143(self) -> None:
-        self.h_prefix = self.create_hash_writer()
-        writers.write_uint32(
-            self.h_prefix, self.tx.version | DECRED_SERIALIZE_NO_WITNESS
-        )
-        write_bitcoin_varint(self.h_prefix, self.tx.inputs_count)
-
     def create_hash_writer(self) -> HashWriter:
         return HashWriter(blake256())
 
+    def create_hash143(self) -> Hash143:
+        return DecredHash(self.h_prefix)
+
     async def step2_approve_outputs(self) -> None:
         write_bitcoin_varint(self.serialized_tx, self.tx.outputs_count)
         write_bitcoin_varint(self.h_prefix, self.tx.outputs_count)
@@ -148,14 +161,8 @@ class Decred(Bitcoin):
         if txo_bin.decred_script_version != 0:
             raise wire.ProcessError("Cannot use utxo that has script_version != 0")
 
-    def hash143_add_input(self, txi: TxInput) -> None:
-        self.write_tx_input(self.h_prefix, txi, bytes())
-
-    def hash143_add_output(self, txo: TxOutput, script_pubkey: bytes) -> None:
-        self.write_tx_output(self.h_prefix, txo, script_pubkey)
-
+    @staticmethod
     def write_tx_input(
-        self,
         w: writers.Writer,
         txi: Union[TxInput, PrevInput],
         script: bytes,
@@ -165,8 +172,8 @@ class Decred(Bitcoin):
         writers.write_uint8(w, txi.decred_tree or 0)
         writers.write_uint32(w, txi.sequence)
 
+    @staticmethod
     def write_tx_output(
-        self,
         w: writers.Writer,
         txo: Union[TxOutput, PrevOutput],
         script_pubkey: bytes,
diff --git a/core/src/apps/bitcoin/sign_tx/hash143.py b/core/src/apps/bitcoin/sign_tx/hash143.py
new file mode 100644
index 000000000..5822c05fd
--- /dev/null
+++ b/core/src/apps/bitcoin/sign_tx/hash143.py
@@ -0,0 +1,85 @@
+from trezor.crypto.hashlib import sha256
+from trezor.messages.PrevTx import PrevTx
+from trezor.messages.SignTx import SignTx
+from trezor.messages.TxInput import TxInput
+from trezor.messages.TxOutput import TxOutput
+from trezor.utils import HashWriter
+
+from apps.common import coininfo
+
+from .. import scripts, writers
+
+if False:
+    from typing import List, Union
+
+
+# BIP-0143 hash
+class Hash143:
+    def __init__(self) -> None:
+        self.h_prevouts = HashWriter(sha256())
+        self.h_sequence = HashWriter(sha256())
+        self.h_outputs = HashWriter(sha256())
+
+    def add_input(self, txi: TxInput) -> None:
+        writers.write_bytes_reversed(
+            self.h_prevouts, txi.prev_hash, writers.TX_HASH_SIZE
+        )
+        writers.write_uint32(self.h_prevouts, txi.prev_index)
+        writers.write_uint32(self.h_sequence, txi.sequence)
+
+    def add_output(self, txo: TxOutput, script_pubkey: bytes) -> None:
+        writers.write_tx_output(self.h_outputs, txo, script_pubkey)
+
+    def preimage_hash(
+        self,
+        txi: TxInput,
+        public_keys: List[bytes],
+        threshold: int,
+        tx: Union[SignTx, PrevTx],
+        coin: coininfo.CoinInfo,
+        sighash_type: int,
+    ) -> bytes:
+        h_preimage = HashWriter(sha256())
+
+        # nVersion
+        writers.write_uint32(h_preimage, tx.version)
+
+        # hashPrevouts
+        prevouts_hash = writers.get_tx_hash(
+            self.h_prevouts, double=coin.sign_hash_double
+        )
+        writers.write_bytes_fixed(h_preimage, prevouts_hash, writers.TX_HASH_SIZE)
+
+        # hashSequence
+        sequence_hash = writers.get_tx_hash(
+            self.h_sequence, double=coin.sign_hash_double
+        )
+        writers.write_bytes_fixed(h_preimage, sequence_hash, writers.TX_HASH_SIZE)
+
+        # outpoint
+        writers.write_bytes_reversed(h_preimage, txi.prev_hash, writers.TX_HASH_SIZE)
+        writers.write_uint32(h_preimage, txi.prev_index)
+
+        # scriptCode
+        script_code = scripts.bip143_derive_script_code(
+            txi, public_keys, threshold, coin
+        )
+        writers.write_bytes_prefixed(h_preimage, script_code)
+
+        # amount
+        writers.write_uint64(h_preimage, txi.amount)
+
+        # nSequence
+        writers.write_uint32(h_preimage, txi.sequence)
+
+        # hashOutputs
+        outputs_hash = writers.get_tx_hash(self.h_outputs, double=coin.sign_hash_double)
+        writers.write_bytes_fixed(h_preimage, outputs_hash, writers.TX_HASH_SIZE)
+
+        # nLockTime
+        writers.write_uint32(h_preimage, tx.lock_time)
+
+        # nHashType
+        writers.write_uint32(h_preimage, sighash_type)
+
+        return writers.get_tx_hash(h_preimage, double=coin.sign_hash_double)
diff --git a/core/src/apps/bitcoin/sign_tx/zcash.py b/core/src/apps/bitcoin/sign_tx/zcash.py
index 45fdd0e08..8af194a3c 100644
--- a/core/src/apps/bitcoin/sign_tx/zcash.py
+++ b/core/src/apps/bitcoin/sign_tx/zcash.py
@@ -26,14 +26,80 @@ from ..writers import (
 )
 from . import approvers, helpers
 from .bitcoinlike import Bitcoinlike
+from .hash143 import Hash143
 
 if False:
+    from apps.common import coininfo
     from typing import List, Union
     from ..writers import Writer
 
 OVERWINTERED = const(0x80000000)
 
 
+class Zip243Hash(Hash143):
+    def __init__(self) -> None:
+        self.h_prevouts = HashWriter(blake2b(outlen=32, personal=b"ZcashPrevoutHash"))
+        self.h_sequence = HashWriter(blake2b(outlen=32, personal=b"ZcashSequencHash"))
+        self.h_outputs = HashWriter(blake2b(outlen=32, personal=b"ZcashOutputsHash"))
+
+    def preimage_hash(
+        self,
+        txi: TxInput,
+        public_keys: List[bytes],
+        threshold: int,
+        tx: Union[SignTx, PrevTx],
+        coin: coininfo.CoinInfo,
+        sighash_type: int,
+    ) -> bytes:
+        h_preimage = HashWriter(
+            blake2b(
+                outlen=32,
+                personal=b"ZcashSigHash" + struct.pack("<I", tx.branch_id),
+            )
+        )
+
+        assert tx.version_group_id is not None
+        assert tx.expiry is not None
+        zero_hash = b"\x00" * TX_HASH_SIZE
+
+        # 1. nVersion | fOverwintered
+        write_uint32(h_preimage, tx.version | OVERWINTERED)
+        # 2. nVersionGroupId
+        write_uint32(h_preimage, tx.version_group_id)
+        # 3. hashPrevouts
+        write_bytes_fixed(h_preimage, get_tx_hash(self.h_prevouts), TX_HASH_SIZE)
+        # 4. hashSequence
+        write_bytes_fixed(h_preimage, get_tx_hash(self.h_sequence), TX_HASH_SIZE)
+        # 5. hashOutputs
+        write_bytes_fixed(h_preimage, get_tx_hash(self.h_outputs), TX_HASH_SIZE)
+        # 6. hashJoinSplits
+        write_bytes_fixed(h_preimage, zero_hash, TX_HASH_SIZE)
+        # 7. hashShieldedSpends
+        write_bytes_fixed(h_preimage, zero_hash, TX_HASH_SIZE)
+        # 8. hashShieldedOutputs
+        write_bytes_fixed(h_preimage, zero_hash, TX_HASH_SIZE)
+        # 9. nLockTime
+        write_uint32(h_preimage, tx.lock_time)
+        # 10. expiryHeight
+        write_uint32(h_preimage, tx.expiry)
+        # 11. valueBalance
+        write_uint64(h_preimage, 0)
+        # 12. nHashType
+        write_uint32(h_preimage, sighash_type)
+        # 13a. outpoint
+        write_bytes_reversed(h_preimage, txi.prev_hash, TX_HASH_SIZE)
+        write_uint32(h_preimage, txi.prev_index)
+        # 13b. scriptCode
+        script_code = derive_script_code(txi, public_keys, threshold, coin)
+        write_bytes_prefixed(h_preimage, script_code)
+        # 13c. value
+        write_uint64(h_preimage, txi.amount)
+        # 13d. nSequence
+        write_uint32(h_preimage, txi.sequence)
+
+        return get_tx_hash(h_preimage)
+
+
 class Zcashlike(Bitcoinlike):
     def __init__(
         self,
@@ -48,6 +114,9 @@ class Zcashlike(Bitcoinlike):
         if self.tx.version != 4:
             raise wire.DataError("Unsupported transaction version.")
 
+    def create_hash143(self) -> Hash143:
+        return Zip243Hash()
+
     async def step7_finish(self) -> None:
         self.write_tx_footer(self.serialized_tx, self.tx)
 
@@ -69,7 +138,9 @@ class Zcashlike(Bitcoinlike):
         threshold: int,
         script_pubkey: bytes,
     ) -> bytes:
-        return self.hash143_preimage_hash(txi, public_keys, threshold)
+        return self.hash143.preimage_hash(
+            txi, public_keys, threshold, self.tx, self.coin, self.get_sighash_type(txi)
+        )
 
     def write_tx_header(
         self, w: Writer, tx: Union[SignTx, PrevTx], witness_marker: bool
@@ -90,70 +161,9 @@ class Zcashlike(Bitcoinlike):
         if tx.version >= 3:
             write_uint32(w, tx.expiry)  # expiryHeight
 
-    # ZIP-0143 / ZIP-0243
-    # ===
-
-    def init_hash143(self) -> None:
-        self.h_prevouts = HashWriter(blake2b(outlen=32, personal=b"ZcashPrevoutHash"))
-        self.h_sequence = HashWriter(blake2b(outlen=32, personal=b"ZcashSequencHash"))
-        self.h_outputs = HashWriter(blake2b(outlen=32, personal=b"ZcashOutputsHash"))
-
-    def hash143_preimage_hash(
-        self, txi: TxInput, public_keys: List[bytes], threshold: int
-    ) -> bytes:
-        h_preimage = HashWriter(
-            blake2b(
-                outlen=32,
-                personal=b"ZcashSigHash" + struct.pack("<I", self.tx.branch_id),
-            )
-        )
-
         assert self.tx.version_group_id is not None
         assert self.tx.expiry is not None
 
-        # 1. nVersion | fOverwintered
-        write_uint32(h_preimage, self.tx.version | OVERWINTERED)
-        # 2. nVersionGroupId
-        write_uint32(h_preimage, self.tx.version_group_id)
-        # 3. hashPrevouts
-        write_bytes_fixed(h_preimage, get_tx_hash(self.h_prevouts), TX_HASH_SIZE)
-        # 4. hashSequence
-        write_bytes_fixed(h_preimage, get_tx_hash(self.h_sequence), TX_HASH_SIZE)
-        # 5. hashOutputs
-        write_bytes_fixed(h_preimage, get_tx_hash(self.h_outputs), TX_HASH_SIZE)
-
-        zero_hash = b"\x00" * TX_HASH_SIZE
-        # 6. hashJoinSplits
-        write_bytes_fixed(h_preimage, zero_hash, TX_HASH_SIZE)
-        # 7. hashShieldedSpends
-        write_bytes_fixed(h_preimage, zero_hash, TX_HASH_SIZE)
-        # 8. hashShieldedOutputs
-        write_bytes_fixed(h_preimage, zero_hash, TX_HASH_SIZE)
-        # 9. nLockTime
-        write_uint32(h_preimage, self.tx.lock_time)
-        # 10. expiryHeight
-        write_uint32(h_preimage, self.tx.expiry)
-        # 11. valueBalance
-        write_uint64(h_preimage, 0)
-        # 12. nHashType
-        write_uint32(h_preimage, self.get_sighash_type(txi))
-
-        # 10a /13a. outpoint
-        write_bytes_reversed(h_preimage, txi.prev_hash, TX_HASH_SIZE)
-        write_uint32(h_preimage, txi.prev_index)
-
-        # 10b / 13b. scriptCode
-        script_code = derive_script_code(txi, public_keys, threshold, self.coin)
-        write_bytes_prefixed(h_preimage, script_code)
-
-        # 10c / 13c. value
-        write_uint64(h_preimage, txi.amount)
-
-        # 10d / 13d. nSequence
-        write_uint32(h_preimage, txi.sequence)
-
-        return get_tx_hash(h_preimage)
-
 
 def derive_script_code(
     txi: TxInput, public_keys: List[bytes], threshold: int, coin: CoinInfo
diff --git a/core/tests/test_apps.bitcoin.segwit.bip143.native_p2wpkh.py b/core/tests/test_apps.bitcoin.segwit.bip143.native_p2wpkh.py
index 79f8ff796..80c780e2d 100644
--- a/core/tests/test_apps.bitcoin.segwit.bip143.native_p2wpkh.py
+++ b/core/tests/test_apps.bitcoin.segwit.bip143.native_p2wpkh.py
@@ -1,8 +1,8 @@
 from common import *
 
+from apps.bitcoin.common import SIGHASH_ALL
 from apps.bitcoin.scripts import output_derive_script
-from apps.bitcoin.sign_tx.approvers import BasicApprover
-from apps.bitcoin.sign_tx.bitcoin import Bitcoin
+from apps.bitcoin.sign_tx.bitcoin import Hash143
 from apps.bitcoin.writers import get_tx_hash
 from apps.common import coins
 from apps.common.keychain import Keychain
@@ -48,17 +48,17 @@ class TestSegwitBip143NativeP2WPKH(unittest.TestCase):
 
     def test_prevouts(self):
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
-        bip143.hash143_add_input(self.inp1)
-        bip143.hash143_add_input(self.inp2)
+        bip143 = Hash143()
+        bip143.add_input(self.inp1)
+        bip143.add_input(self.inp2)
         prevouts_hash = get_tx_hash(bip143.h_prevouts, double=coin.sign_hash_double)
         self.assertEqual(hexlify(prevouts_hash), b'96b827c8483d4e9b96712b6713a7b68d6e8003a781feba36c31143470b4efd37')
 
     def test_sequence(self):
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
-        bip143.hash143_add_input(self.inp1)
-        bip143.hash143_add_input(self.inp2)
+        bip143 = Hash143()
+        bip143.add_input(self.inp1)
+        bip143.add_input(self.inp2)
         sequence_hash = get_tx_hash(bip143.h_sequence, double=coin.sign_hash_double)
         self.assertEqual(hexlify(sequence_hash), b'52b0a642eea2fb7ae638c36f6252b6750293dbe574a806984b8e4d8548339a3b')
 
@@ -66,12 +66,12 @@ class TestSegwitBip143NativeP2WPKH(unittest.TestCase):
 
         seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
+        bip143 = Hash143()
 
         for txo in [self.out1, self.out2]:
             script_pubkey = output_derive_script(txo.address, coin)
             txo_bin = PrevOutput(amount=txo.amount, script_pubkey=script_pubkey)
-            bip143.hash143_add_output(txo_bin, script_pubkey)
+            bip143.add_output(txo_bin, script_pubkey)
 
         outputs_hash = get_tx_hash(bip143.h_outputs, double=coin.sign_hash_double)
         self.assertEqual(hexlify(outputs_hash), b'863ef3e1a92afbfdb97f31ad0fc7683ee943e9abcf2501590ff8f6551f47e5e5')
@@ -80,21 +80,21 @@ class TestSegwitBip143NativeP2WPKH(unittest.TestCase):
 
         seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
-        bip143.hash143_add_input(self.inp1)
-        bip143.hash143_add_input(self.inp2)
+        bip143 = Hash143()
+        bip143.add_input(self.inp1)
+        bip143.add_input(self.inp2)
 
         for txo in [self.out1, self.out2]:
             script_pubkey = output_derive_script(txo.address, coin)
             txo_bin = PrevOutput(amount=txo.amount, script_pubkey=script_pubkey)
-            bip143.hash143_add_output(txo_bin, script_pubkey)
+            bip143.add_output(txo_bin, script_pubkey)
 
         keychain = Keychain(seed, coin.curve_name, [[]])
         node = keychain.derive(self.inp2.address_n)
 
         # test data public key hash
         # only for input 2 - input 1 is not segwit
-        result = bip143.hash143_preimage_hash(self.inp2, [node.public_key()], 1)
+        result = bip143.preimage_hash(self.inp2, [node.public_key()], 1, self.tx, coin, SIGHASH_ALL)
         self.assertEqual(hexlify(result), b'2fa3f1351618b2532228d7182d3221d95c21fd3d496e7e22e9ded873cf022a8b')
 
 
diff --git a/core/tests/test_apps.bitcoin.segwit.bip143.p2wpkh_in_p2sh.py b/core/tests/test_apps.bitcoin.segwit.bip143.p2wpkh_in_p2sh.py
index 70b8445ad..87d62ef20 100644
--- a/core/tests/test_apps.bitcoin.segwit.bip143.p2wpkh_in_p2sh.py
+++ b/core/tests/test_apps.bitcoin.segwit.bip143.p2wpkh_in_p2sh.py
@@ -1,8 +1,8 @@
 from common import *
 
+from apps.bitcoin.common import SIGHASH_ALL
 from apps.bitcoin.scripts import output_derive_script
-from apps.bitcoin.sign_tx.approvers import BasicApprover
-from apps.bitcoin.sign_tx.bitcoin import Bitcoin
+from apps.bitcoin.sign_tx.bitcoin import Hash143
 from apps.bitcoin.writers import get_tx_hash
 from apps.common import coins
 from apps.common.keychain import Keychain
@@ -40,27 +40,27 @@ class TestSegwitBip143(unittest.TestCase):
 
     def test_bip143_prevouts(self):
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
-        bip143.hash143_add_input(self.inp1)
+        bip143 = Hash143()
+        bip143.add_input(self.inp1)
         prevouts_hash = get_tx_hash(bip143.h_prevouts, double=coin.sign_hash_double)
         self.assertEqual(hexlify(prevouts_hash), b'b0287b4a252ac05af83d2dcef00ba313af78a3e9c329afa216eb3aa2a7b4613a')
 
     def test_bip143_sequence(self):
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
-        bip143.hash143_add_input(self.inp1)
+        bip143 = Hash143()
+        bip143.add_input(self.inp1)
         sequence_hash = get_tx_hash(bip143.h_sequence, double=coin.sign_hash_double)
         self.assertEqual(hexlify(sequence_hash), b'18606b350cd8bf565266bc352f0caddcf01e8fa789dd8a15386327cf8cabe198')
 
     def test_bip143_outputs(self):
         seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
+        bip143 = Hash143()
 
         for txo in [self.out1, self.out2]:
             script_pubkey = output_derive_script(txo.address, coin)
             txo_bin = PrevOutput(amount=txo.amount, script_pubkey=script_pubkey)
-            bip143.hash143_add_output(txo_bin, script_pubkey)
+            bip143.add_output(txo_bin, script_pubkey)
 
         outputs_hash = get_tx_hash(bip143.h_outputs, double=coin.sign_hash_double)
         self.assertEqual(hexlify(outputs_hash), b'de984f44532e2173ca0d64314fcefe6d30da6f8cf27bafa706da61df8a226c83')
@@ -68,18 +68,18 @@ class TestSegwitBip143(unittest.TestCase):
     def test_bip143_preimage_testdata(self):
         seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
         coin = coins.by_name(self.tx.coin_name)
-        bip143 = Bitcoin(self.tx, None, coin, BasicApprover(self.tx, coin))
-        bip143.hash143_add_input(self.inp1)
+        bip143 = Hash143()
+        bip143.add_input(self.inp1)
         for txo in [self.out1, self.out2]:
             script_pubkey = output_derive_script(txo.address, coin)
             txo_bin = PrevOutput(amount=txo.amount, script_pubkey=script_pubkey)
-            bip143.hash143_add_output(txo_bin, script_pubkey)
+            bip143.add_output(txo_bin, script_pubkey)
 
         keychain = Keychain(seed, coin.curve_name, [[]])
         node = keychain.derive(self.inp1.address_n)
 
         # test data public key hash
-        result = bip143.hash143_preimage_hash(self.inp1, [node.public_key()], 1)
+        result = bip143.preimage_hash(self.inp1, [node.public_key()], 1, self.tx, coin, SIGHASH_ALL)
         self.assertEqual(hexlify(result), b'6e28aca7041720995d4acf59bbda64eef5d6f23723d23f2e994757546674bbd9')
 
 
diff --git a/core/tests/test_apps.bitcoin.zcash.zip243.py b/core/tests/test_apps.bitcoin.zcash.zip243.py
index 243c22623..fcf5379cb 100644
--- a/core/tests/test_apps.bitcoin.zcash.zip243.py
+++ b/core/tests/test_apps.bitcoin.zcash.zip243.py
@@ -5,11 +5,11 @@ from trezor.messages.TxInput import TxInput
 from trezor.messages.PrevOutput import PrevOutput
 
 from apps.common import coins
+from apps.bitcoin.common import SIGHASH_ALL
 from apps.bitcoin.writers import get_tx_hash
-from apps.bitcoin.sign_tx.approvers import BasicApprover
 
 if not utils.BITCOIN_ONLY:
-    from apps.bitcoin.sign_tx.zcash import Zcashlike
+    from apps.bitcoin.sign_tx.zcash import Zip243Hash
 
 
 # test vectors inspired from https://github.com/zcash-hackworks/zcash-test-vectors/blob/master/zip_0243.py
@@ -191,7 +191,7 @@ class TestZcashZip243(unittest.TestCase):
                 branch_id=v["branch_id"],
             )
 
-            zip243 = Zcashlike(tx, None, coin, BasicApprover(tx, coin))
+            zip243 = Zip243Hash()
 
             for i in v["inputs"]:
                 txi = TxInput(
@@ -201,18 +201,19 @@ class TestZcashZip243(unittest.TestCase):
                     script_type = i["script_type"],
                     sequence = i["sequence"],
                 )
-                zip243.hash143_add_input(txi)
+                zip243.add_input(txi)
+
             for o in v["outputs"]:
                 txo = PrevOutput(
                     amount = o["amount"],
                     script_pubkey = unhexlify(o["script_pubkey"]),
                 )
-                zip243.hash143_add_output(txo, txo.script_pubkey)
+                zip243.add_output(txo, txo.script_pubkey)
 
             self.assertEqual(hexlify(get_tx_hash(zip243.h_prevouts)), v["prevouts_hash"])
             self.assertEqual(hexlify(get_tx_hash(zip243.h_sequence)), v["sequence_hash"])
             self.assertEqual(hexlify(get_tx_hash(zip243.h_outputs)), v["outputs_hash"])
-            self.assertEqual(hexlify(zip243.hash143_preimage_hash(txi, [unhexlify(i["pubkey"])], 1)), v["preimage_hash"])
+            self.assertEqual(hexlify(zip243.preimage_hash(txi, [unhexlify(i["pubkey"])], 1, tx, coin, SIGHASH_ALL)), v["preimage_hash"])
 
 
 if __name__ == "__main__":