re off the shelf cheap des keyseach machine was re corporate jon lnes jon ifi uio no writes a person i know belonging to a research lab of a rivate company claimed to me during a priavte conversation that given the equipment in his lab he could crack a kerberos ticket in minutes to an hour he had access to rather powerful des hardware but not of an extraordinare kind i believe the attack was possible because of the amount of known plaintext in the ticket which itself constitutes a small message this was two years ago i don t believe you and i don t believe your friend why because des is not known to have any known plaintext attacks readily availble unless your friend knows something and is keeping it secret he was bullshitting you now it is possible that he noted a weakness in the implementation of the kerberos protocol for instance using a weak rng to generate keys might cut down on the keyspace not for the user keys for the other kind who s name i can t remember however this is not what was claimed you are claiming a general weakness in des which is not known to exist in the open literature don t get me wrong des is weaker than it should be however cracking it in minutes requires more money be spent on the cracking machine than any organization i know of has available perry metzger pmetzger shearson com laissez faire laissez passer le monde va de lui meme
