Faster hash-based signatures with bounded leakage

Abstract

Digital signatures have become a key component of many embedded system solutions and are facing strong security and efficiency requirements. At the same time side-channel resistance is essential for a signature scheme to be accepted in real-world applications. Based on the Merkle signature scheme and Winternitz one-time signatures we propose a signature scheme with bounded side-channel leakage that is secure in a post-quantum setting. Novel algorithmic improvements for the authentication path computation bound side-channel leakage and improve the average signature computation time by close to 50 % when compared to state-of-the-art algorithms. The proposed scheme is implemented on an Intel Core i7 CPU and an AVR ATxmega microcontroller with carefully optimized versions for the respective target platform. The theoretical algorithmic improvements are verified in the implementations and cryptographic hardware accelerators are used to achieve competitive performance. © 2014 Springer-Verlag.