Efficient post-quantum undeniable signature on 64-bit ARM

Abstract

We present a full-fledged, highly-optimized, constant-time software for post-quantum supersingular isogeny-based undeniable signature (SIUS) on the ARMv8 platforms providing 83- and 110-bit quantum security levels. To the best of our knowledge, this work is the first empirical implementation of isogeny-based quantum-resistant undeniable signature presented to date. The proposed software is developed on the top of our optimized hand-written ARMv8 assembly arithmetic library and benchmarked on a variety of platforms. The entire protocol runs less than a second on Huawei Nexus smart phone, providing 83-bit quantum security level. Moreover, our signature and public key sizes are 25% smaller than the original SIUS scheme. We remark that the SIUS protocol, similar to other isogeny-based schemes, suffers from the excessive number of operations, affecting its overall performance. Nonetheless, its significantly smaller key and signature sizes make it a promising candidate for post-quantum cryptography.