Efficient representations on Koblitz curves with resistance to side channel attacks

Koblitz curves belong to a special class of binary curves on which the scalar multiplication can be computed very efficiently. For this reason, they are suitable candidates for implementations on low-end processors. However, such devices are often vulnerable to side channel attacks. In this paper, we propose two countermeasures against side channel attacks on Koblitz curves. Both of them utilize a fixed-pattern receding to defeat simple power analysis. Our first technique extends a known countermeasure to the special case of Koblitz curves. In our second technique, the scalar is recoded from left to right, and can be easily stored or even randomly generated.