Multi-channel Attacks

We introduce multi-channel attacks, i.e., side-channel attacks which utilize multiple side-channels such as power and EM simultaneously. We propose an adversarial model which combines a CMOS leakage model and the maximum-likelihood principle for performing and analyzing such attacks. This model is essential for deriving the optimal and very often counter-intuitive techniques for channel selection and data analysis. We show that using multiple channels is better for template attacks by experimentally showing a three-fold reduction in the error probability. Developing sound countermeasures against multi-channel attacks requires a rigorous leakage assessment methodology. Under suitable assumptions and approximations, our model also yields a practical assessment methodology for net information leakage from the power and all available EM channels in constrained devices such as chip-cards. Classical DPA/DEMA style attacks assume an adversary weaker than that of our model. For this adversary,...

• Type: Conference
• Year: 2003
• Where: CHES
• Authors: Dakshi Agrawal, Josyula R. Rao, Pankaj Rohatgi
• Keywords: CHES 2003, CMOS Leakage Model, Cryptography, Multi-channel Attacks, Side-channel Attacks