Author: Ethan Heilman 2017-02-25 18:36:49
Published on: 2017-02-25T18:36:49+00:00
The discussion on Bitcoin-dev mailing list is about the security of RIPEMD-160 hash function used in Bitcoin. Ethan Heilman argues that 160-bits are not enough for collision resistance, and finding collisions in RIPEMD-160(SHA-256(msg)) is possible with 2^80 queries. Alice Wonder points out that finding a collision in RIPEMD-160(SHA-256(msg)) that is also a valid SHA-256 hash is much more difficult. However, it is mentioned that finding a collision in RIPEMD-160(SHA-256(msg)) via brute force is not particularly more difficult than finding a collision in RIPEMD-160. If a collision in RIPEMD-160(SHA-256(msg)) is found, it also provides a valid SHA-256 hash for which the preimage is known. The Bitcoin network currently performs roughly SHA-256 ~2^78 queries per day or 2^80 queries every four days.
Updated on: 2023-06-11T21:48:17.738923+00:00