Differential Electromagnetic Attack on an FPGA Implementation of Elliptic Curve Cryptosystems

This paper describes a differential electromagnetic analysis attack performed on a hardware implementation of an elliptic curve cryptosystem. We describe the use of the distance of mean test. The number of measurements needed to get a clear idea of the right guess of the key-bit is taken as indication of the success of the attack. We can find the right key-bit by using only 2000 measurements. Also we give a electromagnetic model for the FPGA we use in our experiments. The amplitude, the direction and the position of the current on the FPGA´s lines with respect to the position of the antenna have an influence on the measured electromagnetic radiation in the FPGA´s surrounding area.