Investigations of Power Analysis Attacks on Smartcards

This paper presents actual results from monitoring smartcard power signals and introduces techniques that help maximize such side-channel information. Adversaries will obviously choose attacks that maximize side-channel information, so it is very important that the strongest attacks be considered when designing defensive strategies. In this paper, power analysis techniques used to attack DES are reviewed and analyzed. The noise characteristics of the power signals are examined and an approach to model the signal to noise ratio is proposed. Test results from monitoring power signals are provided. Next, approaches to maximize the information content of the power signals are developed and tested. These results provide guidance for designing smartcard solutions that are secure against power analysis attacks.