byte2019

Probably a bit of both tbh. If you actually pull the earliest Satoshi client and try rewriting parts of it, you start to get a feel for what was deliberate vs what was just whatever worked. Worth noting the very first…

Length extension attacks, sure, that's the usual answer. But here's the thing: SHA256d shows up all over the place in Bitcoin, transaction hashing, sighash computation, Merkle trees, everywhere. Satoshi wrote it once…