AES crypto broken by 'groundbreaking' attack

Anonymous Coward
Boffin

define "Broken"

Sorry chaps,but there are so many comments bitching about the - actually correct - use of the term broken, that an explanatory footnote should be added.

Broken, in cryptographic circles, means that a means exists for deducing the encryption key, with certainty, in less than the 2^n operations (i.e. complete encryption cycles) that a brute-force attack would require.

Unbroken means the only way to deduce the key is to run through all possibilites and check them - i.e.by "brute force"

Many breaks require additional information, for instance previous AES breaks required either message pairs encrypted with related keys (an unlikely gift) - or, a huge set of ciphertext/plaintext pairs, again an unlikely starting point for a real attack.

This one is a considerable improvement, requiring no additional information. - however, it only loses a couple of bits of key strength - so the cipher is technically "broken", but not "compromised".

Unfortunately the terminology doesn't very well distinguish the level of "break", terms like "very broken" or "completely broken" are seen, but "compromised" seems to be the trigger word that indicates its no longer considered safe to use.

Back to the forum