Fast Dual-Field ECDSA Accelerator with Increased Resistance against Horizontal SCA Attacks

Abstract

Elliptic Curve Cryptography (ECC) is one of the common used standard methods for encrypting and signing messages which is essential when it comes to IoT communication. In this paper we discuss the side channel analysis attack resistance of our fast dual-field ECDSA accelerator. We present our implementation of a design supporting four different NIST Elliptic Curves to allow the reader to understand the discussion of the resistance aspects. Our key findings concerning the resistance are that the dual field design is by far more resistant against SCA than individual designs for B-curves. Here we were able to determine only two key candidates with a correctness above 85% for B-233 compared to the individual design of B-233 for which 6 key candidates with a correctness of more than 95% were revealed. In addition we were able to retrieve 4 candidates with a correctness of more than 97% for P-224 and even 3 fully correct key candidates for P-256. This is especially important as the design for ECs over GF(p) is realized using atomic patterns which is considered in the literature to ensure resistance against horizontal side-channel analysis attacks.