Smaller public keys for MinRank-based schemes

TL;DR

This paper introduces a new key-generation algorithm for MinRank-based cryptographic schemes that significantly reduces public key size while maintaining security, enhancing practicality for post-quantum cryptography.

Contribution

The paper presents a novel key-generation method for MinRank schemes that halves public key size without compromising security, improving efficiency for post-quantum applications.

Findings

Public key size reduced by about 50%.

Public keys range from 328 to 676 bits for 128-256 bit security.

Security equivalent to previous algorithms confirmed.

Abstract

MinRank is an NP-complete problem in linear algebra whose characteristics make it attractive to build post-quantum cryptographic primitives. Several MinRank-based digital signature schemes have been proposed. In particular, two of them, MIRA and MiRitH, have been submitted to the NIST Post-Quantum Cryptography Standardization Process. In this paper, we propose a key-generation algorithm for MinRank-based schemes that reduces the size of the public key to about 50% of the size of the public key generated by the previous best (in terms of public-key size) algorithm. Precisely, the size of the public key generated by our algorithm sits in the range of 328-676 bits for security levels of 128-256 bits. We also prove that our algorithm is as secure as the previous ones.