Novel hardening techniques against differential power analysis for multiplication in GF(2ⁿ)

Abstract

Side channel attacks have changed the design of secure cryptosystems dramatically. Today a reasonable designed cryptosystem has not only to be cryptographically secure, but resistant against side channel attacks as well. Therefore, a lot of countermeasure techniques have been developed in the last years to avoid exploitable information leaking. In this paper we introduce a new approach to secure the multiplication in GF(2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sup> ), an essential operation of elliptic curve cryptography, against differential power analysis attacks. Our hiding technique improves the resistance of a multiplier, even if the attacker has strong knowledge about its architecture. It is scalable and allows to choose arbitrary trade-offs between performance and side channel resistance. The additional costs to secure the multiplier are very low compared to other countermeasures.