Wavelet: Code-based postquantum signatures with fast verification on microcontrollers

TL;DR

This paper introduces Wavelet, a fast, code-based postquantum signature scheme optimized for embedded devices, with significant improvements in verification speed and practical implementation details for microcontrollers.

Contribution

It presents the first full implementation of Wavelet, a postquantum signature scheme with optimized verification for microcontrollers, including handling large public keys and performance enhancements.

Findings

Verification is approximately 4.65 times faster than the original.

Wavelet signatures are 930 bytes, with a 3161 kB public key.

Verification takes 1,087,538 cycles using AVX instructions.

Abstract

This work presents the first full implementation of Wave, a postquantum code-based signature scheme. We define Wavelet, a concrete Wave scheme at the 128-bit classical security level (or NIST postquantum security Level 1) equipped with a fast verification algorithm targeting embedded devices. Wavelet offers 930-byte signatures, with a public key of 3161 kB. We include implementation details using AVX instructions, and on ARM Cortex-M4, including a solution to deal with Wavelet's large public keys, which do not fit in the SRAM of a typical embedded device. Our verification algorithm is $\approx 4.65 \times$ faster then the original, and verifies in 1 087 538 cycles using AVX instructions, or 13 172 ticks in an ARM Cortex-M4.