This paper presents an improved Plantard’s modular arithmetic (Plantard arithmetic) tailored for Lattice-Based Cryptography (LBC). Based on the Plantard arithmetic, we present faster implementations of two LBC schemes, Kyber and NTTRU, running Cortex-M4. The intrinsic advantage is that one multiplication can be saved from a constant. However, original not very practical in schemes because limit...

At CRYPTO’93, Stern proposed a 3-pass code-based identification scheme with a cheating probability of 2/3. In this paper, we propose a 5-pass code-based protocol with a lower communication complexity, allowing an impersonator to succeed with only a probability of 1/2. Furthermore, we propose to use double-circulant construction in order to dramatically reduce the size of the public key. The pro...

The concept of threshold ring signature in code-based cryptography was introduced by Aguilar et al. in [1]. Their proposal uses Stern’s identification scheme as basis. In this paper we construct a novel threshold ring signature scheme built on the q-SD identification scheme recently proposed by Cayrel et al. in [14]. Our proposed scheme benefits of a performance gain as a result of the reductio...