Merge bitcoin#30658: kernel: pre-28.x chainparams and headerssync update

221809b headerssync: Update headerssync configuration (Ava Chow)
c270744 params: Update assumevalid and minimum chainwork (Ava Chow)
255d451 params: Update chainTxData (Ava Chow)
6a5bdae params: Update assumed blockchain and chainstate sizes (Ava Chow)

Pull request description:

  Update chainparams and headerssync parameters for the pre-28.x branching, per https://github.com/bitcoin/bitcoin/blob/master/doc/release-process.md#before-branch-off

ACKs for top commit:
  fjahr:
    re-ACK 221809b
  Sjors:
    re-ACK 221809b
  glozow:
    ACK 221809b
  marcofleon:
    ACK 221809b

Tree-SHA512: 5106d59f46dbe167fffa339519e52975ae5bfd7e52202d76ec058da0d4e8bf87355e90678f7ace7c8c402a2f7264050a0355680b9f727c7962ff60e8fcdb3a90

Author: glozow

contrib/devtools/headerssync-params.py

@@ -12,13 +12,13 @@
 # Parameters:
 
 # Aim for still working fine at some point in the future. [datetime]
-TIME = datetime(2026, 10, 5)
+TIME = datetime(2027, 4, 1)
 
 # Expected block interval. [timedelta]
 BLOCK_INTERVAL = timedelta(seconds=600)
 
 # The number of headers corresponding to the minchainwork parameter. [headers]
-MINCHAINWORK_HEADERS = 804000
+MINCHAINWORK_HEADERS = 856760
 
 # Combined processing bandwidth from all attackers to one victim. [bit/s]
 # 6 Gbit/s is approximately the speed at which a single thread of a Ryzen 5950X CPU thread can hash

src/headerssync.cpp

@@ -13,11 +13,11 @@
 // contrib/devtools/headerssync-params.py.
 
 //! Store one header commitment per HEADER_COMMITMENT_PERIOD blocks.
-constexpr size_t HEADER_COMMITMENT_PERIOD{606};
+constexpr size_t HEADER_COMMITMENT_PERIOD{615};
 
 //! Only feed headers to validation once this many headers on top have been
 //! received and validated against commitments.
-constexpr size_t REDOWNLOAD_BUFFER_SIZE{14441}; // 14441/606 = ~23.8 commitments
+constexpr size_t REDOWNLOAD_BUFFER_SIZE{14621}; // 14621/615 = ~23.8 commitments
 
 // Our memory analysis assumes 48 bytes for a CompressedHeader (so we should
 // re-calculate parameters if we compress further)

src/kernel/chainparams.cpp

@@ -115,8 +115,8 @@ class CMainParams : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1628640000; // August 11th, 2021
         consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 709632; // Approximately November 12th, 2021
 
-        consensus.nMinimumChainWork = uint256{"000000000000000000000000000000000000000063c4ebd298db40af57541800"};
-        consensus.defaultAssumeValid = uint256{"000000000000000000026811d149d4d261995ec5b3f64f439a0a10e1a464af9a"}; // 824000
+        consensus.nMinimumChainWork = uint256{"000000000000000000000000000000000000000088e186b70e0862c193ec44d6"};
+        consensus.defaultAssumeValid = uint256{"000000000000000000011c5890365bdbe5d25b97ce0057589acaef4f1a57263f"}; // 856760
 
         /**
          * The message start string is designed to be unlikely to occur in normal data.
@@ -129,8 +129,8 @@ class CMainParams : public CChainParams {
         pchMessageStart[3] = 0xd9;
         nDefaultPort = 8333;
         nPruneAfterHeight = 100000;
-        m_assumed_blockchain_size = 600;
-        m_assumed_chain_state_size = 10;
+        m_assumed_blockchain_size = 620;
+        m_assumed_chain_state_size = 14;
 
         genesis = CreateGenesisBlock(1231006505, 2083236893, 0x1d00ffff, 1, 50 * COIN);
         consensus.hashGenesisBlock = genesis.GetHash();
@@ -194,10 +194,10 @@ class CMainParams : public CChainParams {
         };
 
         chainTxData = ChainTxData{
-            // Data from RPC: getchaintxstats 4096 000000000000000000026811d149d4d261995ec5b3f64f439a0a10e1a464af9a
-            .nTime    = 1704194835,
-            .tx_count = 946728933,
-            .dTxRate  = 6.569290261471664,
+            // Data from RPC: getchaintxstats 4096 000000000000000000011c5890365bdbe5d25b97ce0057589acaef4f1a57263f
+            .nTime    = 1723649144,
+            .tx_count = 1059312821,
+            .dTxRate  = 6.721086701157182,
         };
     }
 };
@@ -240,17 +240,17 @@ class CTestNetParams : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = 1628640000; // August 11th, 2021
         consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay
 
-        consensus.nMinimumChainWork = uint256{"000000000000000000000000000000000000000000000c59b14e264ba6c15db9"};
-        consensus.defaultAssumeValid = uint256{"000000000001323071f38f21ea5aae529ece491eadaccce506a59bcc2d968917"}; // 2550000
+        consensus.nMinimumChainWork = uint256{"000000000000000000000000000000000000000000000f209695166be8b61fa9"};
+        consensus.defaultAssumeValid = uint256{"000000000000000465b1a66c9f386308e8c75acef9201f3f577811da09fc90ad"}; // 2873500
 
         pchMessageStart[0] = 0x0b;
         pchMessageStart[1] = 0x11;
         pchMessageStart[2] = 0x09;
         pchMessageStart[3] = 0x07;
         nDefaultPort = 18333;
         nPruneAfterHeight = 1000;
-        m_assumed_blockchain_size = 42;
-        m_assumed_chain_state_size = 3;
+        m_assumed_blockchain_size = 93;
+        m_assumed_chain_state_size = 19;
 
         genesis = CreateGenesisBlock(1296688602, 414098458, 0x1d00ffff, 1, 50 * COIN);
         consensus.hashGenesisBlock = genesis.GetHash();
@@ -295,10 +295,10 @@ class CTestNetParams : public CChainParams {
         };
 
         chainTxData = ChainTxData{
-            // Data from RPC: getchaintxstats 4096 000000000001323071f38f21ea5aae529ece491eadaccce506a59bcc2d968917
-            .nTime    = 1703579240,
-            .tx_count = 67845391,
-            .dTxRate  = 1.464436832560951,
+            // Data from RPC: getchaintxstats 4096 000000000000000465b1a66c9f386308e8c75acef9201f3f577811da09fc90ad
+            .nTime    = 1723613341,
+            .tx_count = 187917082,
+            .dTxRate  = 3.265051477698455,
         };
     }
 };
@@ -339,16 +339,16 @@ class CTestNet4Params : public CChainParams {
         consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
         consensus.vDeployments[Consensus::DEPLOYMENT_TAPROOT].min_activation_height = 0; // No activation delay
 
-        consensus.nMinimumChainWork = uint256{"000000000000000000000000000000000000000000000056faca98a0cd9bdf5f"};
-        consensus.defaultAssumeValid = uint256{};
+        consensus.nMinimumChainWork = uint256{"00000000000000000000000000000000000000000000005faa15d02e6202f3ba"};
+        consensus.defaultAssumeValid = uint256{"000000005be348057db991fa5d89fe7c4695b667cfb311391a8db374b6f681fd"}; // 39550
 
         pchMessageStart[0] = 0x1c;
         pchMessageStart[1] = 0x16;
         pchMessageStart[2] = 0x3f;
         pchMessageStart[3] = 0x28;
         nDefaultPort = 48333;
         nPruneAfterHeight = 1000;
-        m_assumed_blockchain_size = 0;
+        m_assumed_blockchain_size = 1;
         m_assumed_chain_state_size = 0;
 
         const char* testnet4_genesis_msg = "03/May/2024 000000000000000000001ebd58c244970b3aa9d783bb001011fbe8ea8e98e00e";
@@ -394,9 +394,10 @@ class CTestNet4Params : public CChainParams {
         };
 
         chainTxData = ChainTxData{
-            .nTime    = 0,
-            .tx_count = 0,
-            .dTxRate  = 0,
+            // Data from RPC: getchaintxstats 4096 000000005be348057db991fa5d89fe7c4695b667cfb311391a8db374b6f681fd
+            .nTime    = 1723651702,
+            .tx_count = 757229,
+            .dTxRate  = 0.01570402633472492,
         };
     }
 };
@@ -420,15 +421,15 @@ class SigNetParams : public CChainParams {
             vSeeds.emplace_back("178.128.221.177");
             vSeeds.emplace_back("v7ajjeirttkbnt32wpy3c6w3emwnfr3fkla7hpxcfokr3ysd3kqtzmqd.onion:38333");
 
-            consensus.nMinimumChainWork = uint256{"00000000000000000000000000000000000000000000000000000206e86f08e8"};
-            consensus.defaultAssumeValid = uint256{"0000000870f15246ba23c16e370a7ffb1fc8a3dcf8cb4492882ed4b0e3d4cd26"}; // 180000
-            m_assumed_blockchain_size = 1;
+            consensus.nMinimumChainWork = uint256{"0000000000000000000000000000000000000000000000000000025dbd66e58f"};
+            consensus.defaultAssumeValid = uint256{"0000014aad1d58dddcb964dd749b073374c6306e716b22f573a2efe68d414539"}; // 208800
+            m_assumed_blockchain_size = 2;
             m_assumed_chain_state_size = 0;
             chainTxData = ChainTxData{
-                // Data from RPC: getchaintxstats 4096 0000000870f15246ba23c16e370a7ffb1fc8a3dcf8cb4492882ed4b0e3d4cd26
-                .nTime    = 1706331472,
-                .tx_count = 2425380,
-                .dTxRate  = 0.008277759863833788,
+                // Data from RPC: getchaintxstats 4096 0000014aad1d58dddcb964dd749b073374c6306e716b22f573a2efe68d414539
+                .nTime    = 1723655233,
+                .tx_count = 5507045,
+                .dTxRate  = 0.06271073277261494,
             };
         } else {
             bin = *options.challenge;