Sign-Based differential power analysis

Abstract

Differential Power Analysis (DPA) by Paul Kocher et al. is expanded with the information that is hidden in the sign of power biases. The latter reveal values that collide with the DPA target value within the circuitry. With the help of cross-iteration comparisons, the interpretation of those values can provide significant amounts of the information required to reverse engineer secret algorithm. We have successfully launched a demonstration attack on a secret authentication and sessionkey generation algorithm implemented on SIM cards in GSM networks. The findings provide guidance for designing tamper resistant devices that are secure against this kind of attack. © Springer-Verlag 2004.