Cryptographic Properties of the Quantum Hashing Based on Expander Graphs

Quantum hashing is a useful technique in different computational and cryptographic scenarios in the quantum world. A set of random parameters is required to construct a quantum hashing scheme. For instance, random walks on expander graphs (expanders) are known to be efficient randomness generators in many areas of computer science. We analyze a scheme based on expanders. Collision resistance and preimage resistance of this scheme are considered. We show that quantum hashing based on expanders is collision-resistant (in quantum sense), and the considered scheme's accessible information is O(1).