SHA-1 Broken - Schneier on Security

SHA-1 has been broken. Not a reduced-round version. Not a simplified version. The real thing. The research team of Xiaoyun Wang, Yiqun Lisa Yin, and Hongbo Yu (mostly from Shandong University in China) have been quietly circulating a paper describing their results: collisions in the the full SHA-1 in 2**69 hash operations, much less than the brute-force attack of 2**80 operations based on the hash length. collisions in SHA-0 in 2**39 operations. collisions in 58-round SHA-1 in 2**33 operations. This attack builds on previous attacks on SHA-0 and SHA-1, and is a major, major cryptanalytic result. It pretty much puts a bullet into SHA-1 as a hash function for digital signatures (although it doesn’t affect applications such as HMAC where collisions aren’t important)...