SPARX - A Side-Channel Protected Processor for ARX-based Cryptography

Florian Bache, Tobias Schneider, Amir Moradi, Tim Güneysu

De­sign, Au­to­ma­ti­on & Test in Eu­ro­pe Con­fe­rence & Ex­hi­bi­ti­on, DATE 2017, Lausanne, Switzerland, March 27 - 31 , 2017, to appear.


ARX-based cryptographic algorithms are composed of only three elemental operations — addition, rotation and exclusive or - which are mixed to ensure adequate confusion and diffusion properties. While ARX-ciphers can easily be protected against timing attacks, special measures like masking have to be taken in order to prevent power and electromagnetic analysis. In this paper we present a processor architecture for ARX-based cryptography, that intrinsically guarantees first-order SCA resistance of any implemented algorithm. This is achieved by protecting the complete data path using a Boolean masking scheme with three shares. We evaluate our security claims by mapping an ARX-algorithm to the proposed architecture and using the common leakage detection methodology based on Student’s t-test to certify the side-channel resistance of our processor.

Tags: hardware implementations, Side-channel countermeasures, Thres­hold Im­ple­men­ta­ti­on