Computational methods in discrete mathematics

Preimage attack on 5-round cryptographic hash function JH-256 via parallel SAT solver

O. S. Zaikin


Abstract: In 2010, the cryptographic hash function JH-256 became a finalist of the SHA-3 competition as a part of the JH family. The main JH-256's component is a 42-round compression function. Consider the following problem: given a zero hash produced by a weakened version of JH-256, where only the first 5 rounds of the compression function are used, find a preimage. This problem was reduced to an instance of the SAT problem. All parallel SAT solvers from the SAT Competition 2024 were tried on the constructed CNF. As a result, one solver found a preimage in reasonable time. Earlier, a preimage for at most 4 rounds of JH-256 was found in practice.

Keywords: cryptographic hash function, JH, preimage attack, Boolean satisfiability problem, SAT.

UDC: 004.8

DOI: 10.17223/2226308X/18/56