darosior · darosior · Apr 30, 2026 · Jan 20, 2026 · Sep 4, 2025 · Oct 14, 2025
diff --git a/doc/bips.md b/doc/bips.md
@@ -18,6 +18,7 @@ BIPs that are implemented by Bitcoin Core:
 * [`BIP 43`](https://github.com/bitcoin/bips/blob/master/bip-0043.mediawiki): The experimental descriptor wallets introduced in **v0.21.0** by default use the Hierarchical Deterministic Wallet derivation proposed by BIP 43. ([PR #16528](https://github.com/bitcoin/bitcoin/pull/16528))
 * [`BIP 44`](https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki): The experimental descriptor wallets introduced in **v0.21.0** by default use the Hierarchical Deterministic Wallet derivation proposed by BIP 44. ([PR #16528](https://github.com/bitcoin/bitcoin/pull/16528))
 * [`BIP 49`](https://github.com/bitcoin/bips/blob/master/bip-0049.mediawiki): The experimental descriptor wallets introduced in **v0.21.0** by default use the Hierarchical Deterministic Wallet derivation proposed by BIP 49. ([PR #16528](https://github.com/bitcoin/bitcoin/pull/16528))
+* [`BIP 54`](https://github.com/bitcoin/bips/blob/master/bip-0054.md): Validation rules for the Consensus Cleanup soft fork are implemented as of version **v32.0**. No deployment is defined for the soft fork, outside of regtest where the rules are now always active.
 * [`BIP 61`](https://github.com/bitcoin/bips/blob/master/bip-0061.mediawiki): The 'reject' protocol message (and the protocol version bump to 70002) was added in **v0.9.0** ([PR #3185](https://github.com/bitcoin/bitcoin/pull/3185)). Starting **v0.17.0**, whether to send reject messages can be configured with the `-enablebip61` option, and support is deprecated (disabled by default) as of **v0.18.0**. Support was removed in **v0.20.0** ([PR #15437](https://github.com/bitcoin/bitcoin/pull/15437)).
 * [`BIP 65`](https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki): The CHECKLOCKTIMEVERIFY softfork was merged in **v0.12.0** ([PR #6351](https://github.com/bitcoin/bitcoin/pull/6351)), and backported to **v0.11.2** and **v0.10.4**. Mempool-only CLTV was added in [PR #6124](https://github.com/bitcoin/bitcoin/pull/6124).
 * [`BIP 66`](https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki): The strict DER rules and associated version 3 blocks have been implemented since **v0.10.0** ([PR #5713](https://github.com/bitcoin/bitcoin/pull/5713)).

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -115,6 +115,7 @@ add_library(bitcoin_common STATIC EXCLUDE_FROM_ALL
   common/system.cpp
   common/url.cpp
   compressor.cpp
+  consensus/tx_verify.cpp
   core_io.cpp
   deploymentinfo.cpp
   external_signer.cpp
@@ -188,7 +189,6 @@ add_library(bitcoin_node STATIC EXCLUDE_FROM_ALL
   bip324.cpp
   blockencodings.cpp
   blockfilter.cpp
-  consensus/tx_verify.cpp
   dbwrapper.cpp
   deploymentstatus.cpp
   flatfile.cpp

diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h
@@ -27,11 +27,26 @@ static const size_t MIN_SERIALIZABLE_TRANSACTION_WEIGHT = WITNESS_SCALE_FACTOR *
 /** Interpret sequence numbers as relative lock-time constraints. */
 static constexpr unsigned int LOCKTIME_VERIFY_SEQUENCE = (1 << 0);
 
+/**
+ * Under BIP54, the first block in a difficulty adjustment period must not be more than 2
+ * hours (7200 seconds) earlier than the last block of the previous period.
+ */
+static constexpr int64_t MAX_TIMEWARP_BIP54{2 * 60 * 60};
+
 /**
  * Maximum number of seconds that the timestamp of the first
  * block of a difficulty adjustment period is allowed to
  * be earlier than the last block of the previous period (BIP94).
  */
-static constexpr int64_t MAX_TIMEWARP = 600;
+static constexpr int64_t MAX_TIMEWARP_TESTNET4 = 600;
+
+/** The maximum number of potentially executed legacy signature operations in a single tx */
+static constexpr unsigned int MAX_TX_BIP54_SIGOPS{2'500};
+
+/**
+ * 64-byte transactions are invalid (BIP 54) due to serious flaws in the Merkle tree algorithm
+ * that make it so that such transactions may be re-interpreted as inner tree nodes.
+ */
+static constexpr unsigned int INVALID_TX_NONWITNESS_SIZE{64};
 
 #endif // BITCOIN_CONSENSUS_CONSENSUS_H
diff --git a/src/consensus/params.h b/src/consensus/params.h
@@ -36,6 +36,7 @@ constexpr bool ValidDeployment(BuriedDeployment dep) { return dep <= DEPLOYMENT_
 
 enum DeploymentPos : uint16_t {
     DEPLOYMENT_TESTDUMMY,
+    DEPLOYMENT_CONSENSUSCLEANUP, // Deployment of BIP 54
     // NOTE: Also add new deployments to VersionBitsDeploymentInfo in deploymentinfo.cpp
     // Removing an entry may require bumping MinBIP9WarningHeight.
     MAX_VERSION_BITS_DEPLOYMENTS

diff --git a/src/consensus/tx_verify.cpp b/src/consensus/tx_verify.cpp
@@ -161,14 +161,44 @@ int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& i
     return nSigOps;
 }
 
-bool Consensus::CheckTxInputs(const CTransaction& tx, TxValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, CAmount& txfee)
+bool Consensus::CheckSigopsBIP54(const CTransaction& tx, const CCoinsViewCache& inputs)
+{
+    Assert(!tx.IsCoinBase());
+
+    unsigned int sigops{0};
+    for (const auto& txin: tx.vin) {
+        const auto& prev_txo{inputs.AccessCoin(txin.prevout).out};
+
+        // Unlike the existing block wide sigop limit which counts sigops present in the block
+        // itself (including the scriptPubKey which is not executed until spending later), BIP54
+        // counts sigops in the block where they are potentially executed (only).
+        // This means sigops in the spent scriptPubKey count toward the limit.
+        // `fAccurate` means correctly accounting sigops for CHECKMULTISIGs(VERIFY) with 16 pubkeys
+        // or fewer. This method of accounting was introduced by BIP16, and BIP54 reuses it.
+        // The GetSigOpCount call on the previous scriptPubKey counts both bare and P2SH sigops.
+        sigops += txin.scriptSig.GetSigOpCount(/*fAccurate=*/true);
+        sigops += prev_txo.scriptPubKey.GetSigOpCount(txin.scriptSig);
+
+        if (sigops > MAX_TX_BIP54_SIGOPS) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool Consensus::CheckTxInputs(const CTransaction& tx, TxValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, CAmount& txfee, bool enforce_bip54)
 {
     // are the actual inputs available?
     if (!inputs.HaveInputs(tx)) {
         return state.Invalid(TxValidationResult::TX_MISSING_INPUTS, "bad-txns-inputs-missingorspent",
                          strprintf("%s: inputs missing/spent", __func__));
     }
 
+    if (enforce_bip54 && !Consensus::CheckSigopsBIP54(tx, inputs)) {
+        return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-legacy-sigops", "too many legacy sigops (BIP54)");
+    }
+
     CAmount nValueIn = 0;
     for (unsigned int i = 0; i < tx.vin.size(); ++i) {
         const COutPoint &prevout = tx.vin[i].prevout;

diff --git a/src/consensus/tx_verify.h b/src/consensus/tx_verify.h
@@ -19,13 +19,19 @@ class TxValidationState;
 /** Transaction validation functions */
 
 namespace Consensus {
+/**
+ * Check the total number of non-witness sigops across the whole transaction, as per BIP54.
+ */
+bool CheckSigopsBIP54(const CTransaction& tx, const CCoinsViewCache& inputs);
+
 /**
  * Check whether all inputs of this transaction are valid (no double spends and amounts)
  * This does not modify the UTXO set. This does not check scripts and sigs.
  * @param[out] txfee Set to the transaction fee if successful.
+ * @param[in] enforce_bip54 Whether to perform the BIP54 sigops check.
  * Preconditions: tx.IsCoinBase() is false.
  */
-[[nodiscard]] bool CheckTxInputs(const CTransaction& tx, TxValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, CAmount& txfee);
+[[nodiscard]] bool CheckTxInputs(const CTransaction& tx, TxValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, CAmount& txfee, bool enforce_bip54);
 } // namespace Consensus
 
 /** Auxiliary functions for transaction validation (ideally should not be exposed) */

diff --git a/src/deploymentinfo.cpp b/src/deploymentinfo.cpp
@@ -13,6 +13,10 @@ const std::array<VBDeploymentInfo,Consensus::MAX_VERSION_BITS_DEPLOYMENTS> Versi
         .name = "testdummy",
         .gbt_optional_rule = true,
     },
+    VBDeploymentInfo{
+        .name = "consensuscleanup",
+        .gbt_optional_rule = false,
+    },
 };
 
 std::string DeploymentName(Consensus::BuriedDeployment dep)

diff --git a/src/kernel/chainparams.cpp b/src/kernel/chainparams.cpp
@@ -136,6 +136,11 @@ class CMainParams : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1815; // 90%
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
 
+        // Deployment of the Consensus Cleanup (BIP 54)
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].bit = 3;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+
         ApplyDeploymentOptions(opts.dep_opts);
 
         consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000001128750f82f4c366153a3a030"};
@@ -260,6 +265,11 @@ class CTestNetParams : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1512; // 75%
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
 
+        // Deployment of the Consensus Cleanup (BIP 54)
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].bit = 3;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+
         ApplyDeploymentOptions(opts.dep_opts);
 
         consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000017dde1c649f3708d14b6"};
@@ -362,6 +372,11 @@ class CTestNet4Params : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1512; // 75%
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
 
+        // Deployment of the Consensus Cleanup (BIP 54)
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].bit = 3;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+
         ApplyDeploymentOptions(opts.dep_opts);
 
         consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000009a0fe15d0177d086304"};
@@ -507,6 +522,11 @@ class SigNetParams : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 1815; // 90%
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 2016;
 
+        // Deployment of the Consensus Cleanup (BIP 54)
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].bit = 3;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nStartTime = Consensus::BIP9Deployment::NEVER_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+
         ApplyDeploymentOptions(options.dep_opts);
 
         // message start is defined as the first 4 bytes of the sha256d of the block script
@@ -591,6 +611,14 @@ class CRegTestParams : public CChainParams
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].threshold = 108; // 75%
         consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].period = 144; // Faster than normal for regtest (144 instead of 2016)
 
+        // Deployment of the Consensus Cleanup (BIP 54)
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].bit = 3;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nStartTime = Consensus::BIP9Deployment::ALWAYS_ACTIVE;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].min_activation_height = 0; // No activation delay
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].threshold = 108; // 75%
+        consensus.vDeployments[Consensus::DEPLOYMENT_CONSENSUSCLEANUP].period = 144;
+
         consensus.nMinimumChainWork = uint256{};
         consensus.defaultAssumeValid = uint256{};
 

diff --git a/src/node/miner.cpp b/src/node/miner.cpp
@@ -59,10 +59,10 @@ int64_t GetMinimumTime(const CBlockIndex* pindexPrev, const int64_t difficulty_a
     int64_t min_time{pindexPrev->GetMedianTimePast() + 1};
     // Height of block to be mined.
     const int height{pindexPrev->nHeight + 1};
-    // Account for BIP94 timewarp rule on all networks. This makes future
-    // activation safer.
+    // Account for BIP94 timewarp rule on all networks. This makes BIP54
+    // activation safer since BIP94 sets a tighter bound.
     if (height % difficulty_adjustment_interval == 0) {
-        min_time = std::max<int64_t>(min_time, pindexPrev->GetBlockTime() - MAX_TIMEWARP);
+        min_time = std::max<int64_t>(min_time, pindexPrev->GetBlockTime() - MAX_TIMEWARP_TESTNET4);
     }
     return min_time;
 }

diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
@@ -10,6 +10,7 @@
 #include <coins.h>
 #include <consensus/amount.h>
 #include <consensus/consensus.h>
+#include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <policy/feerate.h>
 #include <primitives/transaction.h>
@@ -164,35 +165,6 @@ bool IsStandardTx(const CTransaction& tx, const std::optional<unsigned>& max_dat
     return true;
 }
 
-/**
- * Check the total number of non-witness sigops across the whole transaction, as per BIP54.
- */
-static bool CheckSigopsBIP54(const CTransaction& tx, const CCoinsViewCache& inputs)
-{
-    Assert(!tx.IsCoinBase());
-
-    unsigned int sigops{0};
-    for (const auto& txin: tx.vin) {
-        const auto& prev_txo{inputs.AccessCoin(txin.prevout).out};
-
-        // Unlike the existing block wide sigop limit which counts sigops present in the block
-        // itself (including the scriptPubKey which is not executed until spending later), BIP54
-        // counts sigops in the block where they are potentially executed (only).
-        // This means sigops in the spent scriptPubKey count toward the limit.
-        // `fAccurate` means correctly accounting sigops for CHECKMULTISIGs(VERIFY) with 16 pubkeys
-        // or fewer. This method of accounting was introduced by BIP16, and BIP54 reuses it.
-        // The GetSigOpCount call on the previous scriptPubKey counts both bare and P2SH sigops.
-        sigops += txin.scriptSig.GetSigOpCount(/*fAccurate=*/true);
-        sigops += prev_txo.scriptPubKey.GetSigOpCount(txin.scriptSig);
-
-        if (sigops > MAX_TX_LEGACY_SIGOPS) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
 /**
  * Check transaction inputs.
  *
@@ -208,8 +180,6 @@ static bool CheckSigopsBIP54(const CTransaction& tx, const CCoinsViewCache& inpu
  *    as potential new upgrade hooks.
  *
  * Note that only the non-witness portion of the transaction is checked here.
- *
- * We also check the total number of non-witness sigops across the whole transaction, as per BIP54.
  */
 TxValidationState ValidateInputsStandardness(const CTransaction& tx, const CCoinsViewCache& mapInputs)
 {
@@ -218,11 +188,6 @@ TxValidationState ValidateInputsStandardness(const CTransaction& tx, const CCoin
         return state; // Coinbases don't use vin normally
     }
 
-    if (!CheckSigopsBIP54(tx, mapInputs)) {
-        state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD, "bad-txns-nonstandard-inputs", "non-witness sigops exceed bip54 limit");
-        return state;
-    }
-
     for (unsigned int i = 0; i < tx.vin.size(); i++) {
         const CTxOut& prev = mapInputs.AccessCoin(tx.vin[i].prevout).out;
 

diff --git a/src/policy/policy.h b/src/policy/policy.h
@@ -36,14 +36,13 @@ static constexpr unsigned int MINIMUM_BLOCK_RESERVED_WEIGHT{2000};
 static constexpr unsigned int DEFAULT_BLOCK_MIN_TX_FEE{1};
 /** The maximum weight for transactions we're willing to relay/mine */
 static constexpr int32_t MAX_STANDARD_TX_WEIGHT{400000};
-/** The minimum non-witness size for transactions we're willing to relay/mine: one larger than 64  */
+/** The minimum non-witness size for transactions we're willing to relay/mine: one larger than 64.
+ * BIP54 makes 64-byte transactions invalid, but smaller than that are still non-standard. */
 static constexpr unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE{65};
 /** Maximum number of signature check operations in an IsStandard() P2SH script */
 static constexpr unsigned int MAX_P2SH_SIGOPS{15};
 /** The maximum number of sigops we're willing to relay/mine in a single tx */
 static constexpr unsigned int MAX_STANDARD_TX_SIGOPS_COST{MAX_BLOCK_SIGOPS_COST/5};
-/** The maximum number of potentially executed legacy signature operations in a single standard tx */
-static constexpr unsigned int MAX_TX_LEGACY_SIGOPS{2'500};
 /** Default for -incrementalrelayfee, which sets the minimum feerate increase for mempool limiting or replacement **/
 static constexpr unsigned int DEFAULT_INCREMENTAL_RELAY_FEE{100};
 /** Default for -bytespersigop */

diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
@@ -1508,6 +1508,7 @@ UniValue DeploymentInfo(const CBlockIndex* blockindex, const ChainstateManager&
     SoftForkDescPushBack(blockindex, softforks, chainman, Consensus::DEPLOYMENT_CSV);
     SoftForkDescPushBack(blockindex, softforks, chainman, Consensus::DEPLOYMENT_SEGWIT);
     SoftForkDescPushBack(blockindex, softforks, chainman, Consensus::DEPLOYMENT_TESTDUMMY);
+    SoftForkDescPushBack(blockindex, softforks, chainman, Consensus::DEPLOYMENT_CONSENSUSCLEANUP);
     return softforks;
 }
 } // anon namespace

diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
@@ -19,6 +19,7 @@ add_executable(test_bitcoin
   bech32_tests.cpp
   bip32_tests.cpp
   bip324_tests.cpp
+  bip54_tests.cpp
   blockchain_tests.cpp
   blockencodings_tests.cpp
   blockfilter_index_tests.cpp
@@ -144,6 +145,8 @@ include(TargetDataSources)
 target_json_data_sources(test_bitcoin
   data/base58_encode_decode.json
   data/bip341_wallet_vectors.json
+  data/bip54_coinbases.json
+  data/bip54_timestamps.json
   data/blockfilters.json
   data/key_io_invalid.json
   data/key_io_valid.json