Paper 2015/447

A New Model for Error-Tolerant Side-Channel Cube Attacks

Zhenqi Li, Bin Zhang, Junfeng Fan, and Ingrid Verbauwhede

Abstract

Side-channel cube attacks are a class of leakage attacks on block ciphers in which the attacker is assumed to have access to some leaked information on the internal state of the cipher as well as the plaintext/ciphertext pairs. The known Dinur-Shamir model and its variants require error-free data for at least part of the measurements. In this paper, we consider a new and more realistic model which can deal with the case when \textit{all} the leaked bits are noisy. In this model, the key recovery problem is converted to the problem of decoding a binary linear code over a binary symmetric channel with the crossover probability which is determined by the measurement quality and the cube size. We use the maximum likelihood decoding method to recover the key. As a case study, we demonstrate efficient key recovery attacks on PRESENT. We show that the full $80$-bit key can be restored with $2^{10.2}$ measurements with an error probability of $19.4\%$ for each measurement.