The Davies-Murphy power attack

Abstract

In this paper, we introduce a new power analysis attack against DES. It is based on the well known Davies-Murphy attack. As for the original attack, we take advantage of non-uniform output distributions for two adjacent S-boxes. We show how to detect these biased distributions by power analysis on any DES inner round and thus obtain one bit of information about the key. An advantage of this new attack is that no information about DES inputs or outputs is required. Therefore it is likely to defeat many actual countermeasures, in particular the popular masking techniques. © International Association for Cryptologic Research 2004.