SHA-0 Broken, MD5 Rumored Broken
MD5 Collision Nearly Found
Following up on yesterday's discussion about new attacks on cryptographic
hashfunctions, Eric Rescorla points to a new paper
(http://eprint.iacr.org/2004/199.pdf) from Chinese computer scientists, which
claims to have found a collision in MD5. MD5 is a cousin of the SHA-1 function
discussed yesterday; MD5 is believed to be the weaker of the two.
The paper is odd, in that it includes two values that it claims have the same
MD5 value, but it doesn't explain how the claimed collision was generated. And
it turns out that the authors made an error, so that the two values don't in
fact generate the same MD5 value. Eric and the commenters on his site did some
clever detective work to determine that the two published values generate a
collision for a slightly different function, which Eric dubbed MD5'. MD5' is
very similar to MD5 so it seems very likely that the new attack can be extended
to the real MD5.
Global link:
http://www.freedom-to-tinker.com/archives/2004_08.html