SHA1 collisions make Git vulnerable to attakcs by third-parties, not just repo maintainers



Summary:

In a discussion on the bitcoin-dev mailing list, Ethan Heilman argued that SHA1 is insecure because of flaws in the algorithm rather than the length of its output. He further contended that 160-bits might not be enough for collision resistance, stating that collisions could be generated in 2^80 queries assuming RIPEMD-160(SHA-256(msg)) has no flaws. However, producing a collision that is also a valid SHA-256 hash is much more difficult and requires significantly more computational power. The Bitcoin network, which performs roughly SHA-256 ~2^78 queries per day, would take approximately four days to generate 2^80 queries.


Updated on: 2023-06-11T21:47:16.939426+00:00