Paper 2022/058

First-Order Masked Kyber on ARM Cortex-M4

Abstract

In this work, we present a fast and first-order secure Kyber implementation optimized for ARM Cortex-M4. Most notably, to our knowledge this is the first liberally-licensed open-source Cortex-M4 implementation of masked Kyber. The ongoing NIST standardization process for post-quantum cryptography and newly proposed side-channel attacks have increased the demand for side-channel analysis and countermeasures for the finalists. On the foundation of the commonly used PQM4 project, we make use of the previously presented optimizations for Kyber on a Cortex-M4 and further combine different ideas from various recent works to achieve a better performance and improve the security in comparison to the original implementations. We show our performance results for first-order secure implementations. Our masked Kyber768 decapsulation on the ARM Cortex-M4 requires only 2 978 441 cycles, including randomness generation from the internal RNG. We then practically verify our implementation by using the t-test methodology with 100 000 traces.