Theoretical Use of Cache Memory as a Cryptanalytic Side-Channel.

We expand on the idea, proposed by Kelsey et al. [?], of cache memory being used as a side-channel which leaks information during the run of a cryptographic algorithm. By using this side-channel, an attacker may be able to reveal or narrow the possible values of secret information held on the target device. We describe an attack which encrypts 2 chosen plaintexts on the target processor in order to collect cache profiles and then performs around 2 computational steps to recover the key. As well as describing and simulating the theoretical attack, we discuss how hardware and algorithmic alterations can be used to defend against such techniques.