Abstract

Power analysis attacks against embedded secret key cryptosystems are widely studied since the seminal paper of Paul Kocher, Joshua Ja, and Benjamin Jun in 1998 where has been introduced the powerful Differential Power Analysis. The strength of DPA is such that it became necessary to develop sound and efficient countermeasures. Nowadays embedded cryptographic primitives usually integrate one or several of these countermeasures (e.g. masking techniques, asynchronous designs, balanced dynamic dual-rail gates designs, noise adding, power consumption smoothing, etc....). This document presents a simple, yet interesting, countermeasure to DPA and HO-DPA attacks, called brutal countermeasure and new power analysis attacks using multi-linear approximations (MLPA attacks) based on very recent and still unpublished results of Tavernier et al.. Keywords: Power Analysis, MLPA, multi-linear cryptanalysis, Reed-Muller codes.