DES Sidechannel Collision Attacks On Smartcard Implementations
Kai Schramm · 2002
Until now in cryptography the term collision was mainly associated with the surjective mapping of different inputs to an equal output of a hash function. Previous collision attacks were only able to detect collisions at the output of a particular function. In this thesis a new class of attacks is introduced which uses side channel analysis to detect internal collisions. We applied our attack against the widely used Data Encryption Standard (DES). We show that internal collisions can be caused in the S-Boxes of DES in order to gain information about the secret key-bits. As result, we were able to exploit an internal collision with a minimum of 140 encryptions yielding 10.2 key-bits. Moreover, we successfully applied the attack to a smart card compatible processor. averaged over 10,000 keys