  Quantum hashing is a promising generalization of the cryptographic hashing
concept on the quantum domain. In this paper, we construct a quantum hash via a
sequence of single-photon states and perform a proof-of-principle experiment
using orbital angular momentum (OAM) encoding. We experimentally verify the
collision resistance of the quantum hash function depending on the number of
qubits in use. Based on these results, we conclude that theoretical estimates
are confirmed for different bases of OAM states and the proposed technique can
be useful in computational and cryptographic scenarios. The possibility of
multiplexing different OAM bases can make this approach even more efficient.
