Dan Kreiser

Ievgen Kabin, Zoya Dyka, Dan Kreiser et al.

Side-channel analysis attacks, especially horizontal DPA and DEMA attacks, are significant threats for cryptographic designs. In this paper we investigate to which extend different multiplication formulae and randomization of the field multiplier increase the resistance of an ECC design against horizontal attacks. We implemented a randomized sequence of the calculation of partial products for the field multiplication in order to increase the security features of the field multiplier. Additionally, we use the partial polynomial multiplier itself as a kind of countermeasure against DPA attacks. We demonstrate that the implemented classical multiplication formula can increase the inherent resistance of the whole ECC design. We also investigate the impact of the combination of these two approaches. For the evaluation we synthesized all these designs for a 250 nm gate library technologies, and analysed the simulated power traces. All investigated protection means help to decrease the success rate of attacks significantly: the correctness of the revealed key was decreased from 99% to 69%.

Zoya Dyka, Dan Kreiser, Ievgen Kabin et al.

In this paper we describe our flexible ECDSA design for elliptic curve over binary extended fields GF(2l). We investigated its resistance against Horizontal Collision Correlation Attacks (HCCA). Due to the fact that our design is based on the Montgomery kP algorithm using Lopez-Dahab projective coordinates the scalar k cannot be successful revealed using HCCA, but this kind of attacks can be helpful to divide the measured traces into parts that correspond to processing of a single bit of the scalar k. The most important contribution of this paper is that our flexible field multiplier is resistant against horizontal attacks. This inherent resistance makes it a valuable building block for designing unified field multipliers.

Ievgen Kabin, Zoya Dyka, Dan Kreiser et al.

In this paper we introduce a unified field multiplier for the EC kP operation in two different types of Galois fields. The most important contributions of this paper are that the multiplier is based on the 4-segment Karatsuba multiplication method and that it is inherent resistant against selected horizontal attacks.