Cryptanalysis of a Cayley Hash Function Based on Affine Maps in one Variable over a Finite Field

TL;DR

This paper analyzes the security of a Cayley hash function based on affine maps over finite fields, demonstrating its vulnerability to collision attacks and highlighting its insecurity.

Contribution

It provides a cryptanalysis showing that a recent Cayley hash function construction is insecure due to collision vulnerabilities.

Findings

The hash function is vulnerable to collision attacks.

Previous similar hash functions have been proven insecure.

The paper highlights the importance of rigorous security analysis for cryptographic hash functions.

Abstract

Cayley hash functions are cryptographic hashes constructed from Cayley graphs of groups. The hash function proposed by Shpilrain and Sosnovski (2016), based on linear functions over a finite field, was proven insecure. This paper shows that the proposal by Ghaffari and Mostaghim (2018) that uses the Shpilrain and Sosnovski's hash in its construction is also insecure. We demonstrate its security vulnerability by constructing collisions.