I’ve written up some research on invalid Bitcoin blocks, alongside a catalogue of 143 established cases spanning 2010 to 2026.
These are blocks that met Bitcoin’s PoW requirement but failed a consensus rule. The work started with two recent F2Pool timestamp failures found in merge-mined chains, neither with a known Bitcoin-side capture. You can see both on the merge-mining monitor: April and July.
The post covers the historical failure patterns and how evidence was recovered from auxiliary chains, archived explorers and old node data, including 89 blocks carrying the same P2SH-invalid transaction in 2012.
The catalogue brings together the surviving evidence so each failure can be independently verified, even though 127 cases have no complete block body. I also emphasise the case for monitoring merge-mined chains as a source of both stale and invalid Bitcoin blocks.
I’d also welcome suggestions on how to include and classify descendants of invalid blocks. I opted to hold them out initially, but as Core treats these as invalid, they probably no different than the others, and should be included too!