LESS: Linear Equivalence Signature Scheme

Abstract

LESS (Linear Equivalence Signature Scheme) is a digital signature scheme relying on the hardness of the Linear Code Equivalence Problem, perhaps the first code-based scheme not relying on a variant of the Syndrome Decoding Problem.

This talk explores the foundations, construction, and security of LESS. We also discuss upgrades such as LESS-F, LESS-M, and CF-LESS, and how group actions provide a unifying language to describe its functionality.

Notes

This talk was part of the course Post Quantum Cryptography by Daniele Friolo (Università La Sapienza), who I thank for the great occasion and interesting course.

Material

• slides
• specifics of LESS (v2)

Bibliography

Much of the content builds on papers and preprints published between 2020 and 2025. All references are on the respective slides.