Power analysis of hardware implementations protected with secret sharing

Abstract

We analyze the security of three-share hardware implementations against differential power analysis and advanced variants such as mutual information analysis. We present dedicated distinguishers that allow to recover secret key bits from any cryptographic primitive that is implemented as a sequence of quadratic functions. Starting from the analytical treatment of such distinguishers and information-theoretic arguments, we derive the success probability and required number of traces in the presence of algorithmic noise. We show that attacks on three-share hardware implementation require a number of traces that scales in the third power of the algorithmic noise variance. Finally, we apply and test our model on Keccak in a keyed mode.