Amplified template attack of cryptographic algorithms

This paper presents a new method to implement template based simple power analysis of cryptographic algorithms. Template attacks are most powerful side channel technique to evaluation cryptographic hardware. They use a profiling phase to compute features of a multivariate Gaussian distribution of power signals from a training device and an attack phase to infer cryptographic key on a target device. In this paper we introduce new approach of template attack using minimum distance comparison of signals. Results show distance based template attack leads to higher probability of success respect to Gaussian template attack. Also we present full key bits recovery of A5/1 stream cipher by template based power analysis of key bits initialization. The results of new attack on A5/1 indicate that probability of success key recovery in this method is higher than conventional template attack.