Invalid block 783426

Why it is invalid

rule and Core reject

bad-blk-sigops

Core check

ConnectBlock

CI checks

A complete block at mainnet height 481824 or later, authenticated previous transactions for every external input, and calculated BIP16/BIP141 sigop cost above 80000.

Incident note: 783426 and 784121 - F2Pool sigops (2023)

Both blocks exceed the sigop limit: accurate sigop cost 80003 against the 80000 maximum, counted in ConnectBlock. The context-free legacy count is under the limit, which is why replay cannot reproduce bad-blk-sigops. Documented in b10c observation 11. CI reproduces the 80003 cost for each block using previous transactions authenticated against its inputs. Block 783426 has 74520 legacy cost, 160 P2SH cost and 5323 witness cost; block 784121 has 72204, 908 and 6891 respectively. The previous transactions are fetched from public APIs and cached; the block bodies and their witness commitments supply the remaining evidence.