If an attacker owns 33%, q=0.33, so for a below 0.1% risk of the attacker being able to rewrite the chain, one should wait about 30 blocks, z=30.

You mean no single miner had 33% in the early days?

Lumor

Thanks for that tid-bit of information, thanks.

0x76bda81

bitcoin

POLL: Be HONEST, have you read the Bitcoin whitepaper fully?

birdeye21

Page 8 of the white paper explains why 6-confs are generally considered secure. If you redo the math with a single miner owning 33% of hashrate (like foundry does right now), you would need closer to 20 confs to achieve the same security assurances as 6-confs provided back then