On a NIST-sponsored hash function mailing list, Jesse Walker (from Intel; also a member of the Skein team) did some back-of-the-envelope calculations to estimate how long it will be before we see a practical collision attack against SHA-1. I’m reprinting his analysis here, so it reaches a broader audience. According to E-BASH, the cost of one block of a SHA-1 operation on already deployed commodity microprocessors is about 214 cycles. If Stevens’ attack of 260 SHA-1 operations serves as t...
