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by mst 3400 days ago
Assuming you meant "hide behind", his original attitude seems to be more like "this is sufficiently unlikely in practice that I consider attempting to mitigate it in advance to be overengineering with a higher opportunity cost than it's worth". Which, well, I think when it comes to security stuff he has a nasty tendency to underestimate the risks and thereby pick the wrong side of the trade-off, but to me it's clearly a trade-off rather than something to hide behind.
1 comments

I think it's a reasonable assumption that, as computing power increases, hash functions will be broken. Not that they have to be, but it's reasonable to assume that, and I think it's beyond short-sighted for Torvalds to have failed to build a mechanism in git for hash function migration into git from the very start.
Cryptanalytic research is the fundamental thing that broke SHA-1, not simply the increase in available computing power. So that's not really a 'reasonable assumption', if it was, we could 'reasonably' assume SHA-512 will never be broken.
The point remains, since computing power increases, and cryptanalytic research advances, we really should make sure software that depends on cryptographic hashes has a reasonable way to move to different algorithms. At the very least we could add as a prefix to the resulting hash the name of the algorithm that generated it when we store it.
The advances of research and computing power are vastly outpaced by basic things like digest size. If you came up with a complexity reduction of the order of the one developed against SHA-1 for SHA-256, you won't be able to find any SHA-256 collisions.