kernel: update defaultAssumeValid and minimumChainWork
What the developer wrote
Authored by Ava Chow
kernel: update defaultAssumeValid and minimumChainWork
What changed, and why it matters
This commit updates two routine Bitcoin network parameters—minimumChainWork and defaultAssumeValid—to newer block heights for mainnet, testnet, signet, and regtest. These values are checkpoints that help nodes sync faster by skipping validation of very old blocks. The change is a standard, scheduled maintenance update with no security vulnerability.
No security action required. Treat as routine release maintenance.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The patch bumps consensus.nMinimumChainWork and consensus.defaultAssumeValid to more recent block hashes/heights across CMainParams, CTestNetParams, CRegTestParams (signet section), and default signet parameters. These constants are used by AssumeUTXO/assumevalid logic to set a floor on the proven chain-work and a default block hash assumed to be valid. Updating them is a normal part of Bitcoin Core releases and does not alter consensus rules, introduce a bug, or fix a vulnerability.
Changed components
src/kernel/chainparams.cppInspect captured patch +8 / −8
diff --git a/src/kernel/chainparams.cpp b/src/kernel/chainparams.cpp
index 3b3e1a24..95a2650e 100644
--- a/src/kernel/chainparams.cpp
+++ b/src/kernel/chainparams.cpp
@@ -114,8 +114,8 @@ public:
consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].threshold = 1815; // 90%
consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].period = 2016;
- consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000dee8e2a309ad8a9820433c68"};
- consensus.defaultAssumeValid = uint256{"00000000000000000000611fd22f2df7c8fbd0688745c3a6c3bb5109cc2a12cb"}; // 912683
+ consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000001128750f82f4c366153a3a030"};
+ consensus.defaultAssumeValid = uint256{"00000000000000000000ccebd6d74d9194d8dcdc1d177c478e094bfad51ba5ac"}; // 938343
/**
* The message start string is designed to be unlikely to occur in normal data.
@@ -239,8 +239,8 @@ public:
consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].threshold = 1512; // 75%
consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].period = 2016;
- consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000016dd270dd94fac1d7632"};
- consensus.defaultAssumeValid = uint256{"0000000000000065c6c38258e201971a3fdfcc2ceee0dd6e85a6c022d45dee34"}; // 4550000
+ consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000017dde1c649f3708d14b6"};
+ consensus.defaultAssumeValid = uint256{"000000007a61e4230b28ac5cb6b5e5a0130de37ac1faf2f8987d2fa6505b67f4"}; // 4842348
pchMessageStart[0] = 0x0b;
pchMessageStart[1] = 0x11;
@@ -341,8 +341,8 @@ public:
consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].threshold = 1512; // 75%
consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].period = 2016;
- consensus.nMinimumChainWork = uint256{"00000000000000000000000000000000000000000000034a4690fe592dc49c7c"};
- consensus.defaultAssumeValid = uint256{"000000000000000180a58e7fa3b0db84b5ea76377524894f53660d93ac839d9b"}; // 91000
+ consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000009a0fe15d0177d086304"};
+ consensus.defaultAssumeValid = uint256{"0000000002368b1e4ee27e2e85676ae6f9f9e69579b29093e9a82c170bf7cf8a"}; // 123613
pchMessageStart[0] = 0x1c;
pchMessageStart[1] = 0x16;
@@ -426,8 +426,8 @@ public:
vSeeds.emplace_back("seed.signet.bitcoin.sprovoost.nl.");
vSeeds.emplace_back("seed.signet.achownodes.xyz."); // Ava Chow, only supports x1, x5, x9, x49, x809, x849, xd, x400, x404, x408, x448, xc08, xc48, x40c
- consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000000000000067d328e681a"};
- consensus.defaultAssumeValid = uint256{"000000128586e26813922680309f04e1de713c7542fee86ed908f56368aefe2e"}; // 267665
+ consensus.nMinimumChainWork = uint256{"00000000000000000000000000000000000000000000000000000b463ea0a4b8"};
+ consensus.defaultAssumeValid = uint256{"00000008414aab61092ef93f1aacc54cf9e9f16af29ddad493b908a01ff5c329"}; // 293175
m_assumed_blockchain_size = 24;
m_assumed_chain_state_size = 4;
chainTxData = ChainTxData{
Why this scored 15/100
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