Scabbard: a suite of efficient learning with rounding key-encapsulation mechanisms

Abstract

In this paper, we introduce Scabbard, a suite of post-quantum keyencapsulation mechanisms. Our suite contains three different schemes Florete, Espada, and Sable based on the hardness of module- or ring-learning with rounding problem. In this work, we first show how the latest advancements on lattice-based cryptographycan be utilized to create new better schemes and even improve the state-of-the-art on post-quantum cryptography. We put particular focus on designing schemes that can optimally exploit the parallelism offered by certain hardware platforms and are also suitable for resource constrained devices. We show that this can be achieved without compromising the security of the schemes or penalizing their performance on other platforms.To substantiate our claims, we provide optimized implementations of our three new schemes on a wide range of platforms including general-purpose Intel processors using both portable C and vectorized instructions, embedded platforms such as Cortex-M4 microcontrollers, and hardware platforms such as FPGAs. We show that on each platform, our schemes can outperform the state-of-the-art in speed, memory footprint, or area requirements.

Kavach: Lightweight masking techniques for polynomial arithmetic in lattice-based cryptography

“…They can benefit from hybrid masking unless the scheme makes NTT representation an integral part of the scheme. Our contributions are therefore directly applicable to implementations of algorithms such as SABER [BMD + 20], Scabbard [MKKV21], NTRU [HPS06] or LAC [LLZ + 18]. In the long term, our results should aid future lattice-based scheme design choices (in particular the power-of-two versus NTT-friendly trade-off).…”

“…While the NIST standardization aimed at selecting a portfolio of post-quantum algorithms for general applications, there is a need for developing tailored post-quantum schemes that meet application-specific needs, for example, the constraints of the IoT and automotive applications. In recent years, several new post-quantum algorithms [DPPvW22,MKKV21] have emerged with better performance or security features (or both) than the candidate algorithms in the NIST standardization. Security against side-channel attacks [MOP07] has become an essential requirement in applications where an attacker can obtain side-channel information such as variations in the power consumption or electromagnetic emanation, or temperature of the cryptographic device.…”