alt Hacker NewsLinus Torvalds in 2007:
> but the point is the SHA-1, as far as Git is concerned, isn't even a security feature. It's purely a consistency check. The security parts are elsewhere, so a lot of people assume that since Git uses SHA-1 and SHA-1 is used for cryptographically secure stuff, they think that, Okay, it's a huge security feature. It has nothing at all to do with security, it's just the best hash you can get. ... [1]
[1] https://www.youtube.com/watch?v=4XpnKHJAok8&t=56m20s
So Torvalds used SHA-1 purely because he needed a hash function with no other property than identifying content.
Replies
Exactly. But that's why I think SHA was a mistake. He should have gone with something like murmur to avoid all this frothing at the mouth.
Hard coding a specific hash algorithm was a big mistake.
> It's purely a consistency check. The security parts are elsewhere
Sorry if the video answers this, but how does commit signing work if it doesn't rely on the hash algorithm being resistant to at least second-preimage attacks?