SHA-1 broken, says Schneier

[Andy Isaacson]

>From Bruce Schneier's weblog:
http://www.schneier.com/blog/archives/2005/02/sha1_broken.html

# 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
# announcing 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. This pretty much puts a bullet into
# SHA-1 as a hash function for digital signatures (although it doesn't
# affect applications such as HMAC).
# 
# The paper isn't generally available yet. At this point I can't tell if
# the attack is real, but the paper looks good and this is a reputable
# research team.

This appears to be the same research team that published the MD5
collision technique back in August.

-andy

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