Applying Grover's Algorithm to Hash Functions: A Software Perspective

TL;DR

This paper explores implementing classical hash functions as quantum oracles to evaluate the resource requirements for Grover's Algorithm-based preimage attacks, introducing an optimization for SHA-3 to reduce qubit usage.

Contribution

It demonstrates how to model classical hash functions as quantum oracles and presents an optimization that significantly reduces qubit requirements for SHA-3.

Findings

Reduced qubit count for SHA-3 by 40%

Quantified resource needs for quantum preimage attacks on hash functions

Implemented classical hash functions as quantum oracles

Abstract

Quantum software frameworks provide software engineers with the tools to study quantum algorithms as applied to practical problems. We implement classical hash functions MD5, SHA-1, SHA-2, and SHA-3 as quantum oracles to study the computational resource requirements of conducting a preimage attack with Grover's Algorithm. We introduce an improvement to the SHA-3 oracle that reduces the number of logical qubits required in the Keccak block permutation by 40%.