New, Faster Attack against SHA-1 Revealed

VxSote writes "According to Bruce Schneier's blog, a team of Chinese cryptographers has announced new results against SHA-1 that speed up the time required to find collisions compared to their previously published attack. Schneier says that a SHA-1 collision search is now 'squarely in the realm of feasibility,' and that further improvements are expected."

Comments

Is that the attack...

[RevDobbs]

Is that the same attack the chinese exchange student used in Lineage II?

The world is collapsing around me!

[frinkacheese]

Next there will be massive ASIC machines crunching your PGP ciphertext and nobody will be able to proove anything until Lt Cmdr Data comes up with another Fractal Encryption algorythm that even the Borg cannot break.

Big deal

[That's Unpossible!]

All they did was look for a near-collision
differential path which has low Hamming weight in the "disturbance vector" where each 1-bit represents a 6-step local collision. Then they simply adjusted the differential path in the first round to another possible differential path so as to avoid impossible consecutive local collisions and truncated local collisions. Then obviously the final step taken was to transform two one-block near-collision differential paths into a twoblock
collision differential path with twice the search complexity.

Duh...

Re:Big deal

[gardyloo]

Invariant manifolds? You were lucky! We dreamed of invariant manifolds. We had to make do with symplectic diffeomorphisms of the torus, what with its four fixed points, you know, assuming that the eigenvalues of the Jacobi matrix are not equal to minus unity at any point... and we liked it.

Re:oh God bless them, those kooky spookies

[Anonymous Coward]

The NSA doesn't release its finding about new attacks against encryption algos. They use the info to crack and keep secure. Promote AES as a standard, and have a decades worth of research about useful attacks against AES that no-one knows about but the NSA.

Like public-key encryption. People in Britain discovered it first, but kept the research secret.

Security

[bredk]

I've just changed away from using SHA-1. Double ROT13 seems most appealing these days. ;)

Re:Security

[CRCulver]

SHA-1 isn't a cipher, it's a hash algorithm. Therefore, it has nothing to do with encryption (like ROT13), but with authentication. Sorry to ruin your little joke, which has become a tired amusement lamely presented in every new Slashdot story on cryptography.

Re:Security

[cpeikert]

Wait a minute, you don't sound sorry at all!

Re:Two questions...

[Anonymous Coward]

I think that the greatest threat in this case is not terrorists but the institutions such as government and security forces. Terrorists have a great interest in keeping their own transmissions secure but little interest in the communications of others.

Their tagets are soft, security is fairly low and information can be obtained using people on the street.

Counterintelligence is a game played by large beauracracies who are at peace at the moment but would really like not to be. It involves the use of large ammounts of resources for the main purpose of maintaining the status quo. Terrorists are not interested in the status quo, they want things to change.

Anonymous "team of Chinese cryptographers"

[clap_hands]

Have you ever noticed how you never hear the names of these Chinese researchers...Professor Xiaoyun Wang and her colleagues (for SHA-1, Yiqun Lisa Yin and Hongbo Yu) have broken the greater share of the popular hash functions: MD4, MD5, SHA-0, SHA-1, RIPEMD...and the only name that gets mentioned is "Bruce Schneier reports that Chinese cryptographers...". Not to belittle Schneier, but what these anonymous "Chinese cryptographers" have achieved is exceedingly significant in the field of cryptography, and the least we can do is mention their names occasionally, right?

Even if they are unpronouncable ;-)