  A new version of quantum hashing technique is developed wherein a quantum
hash is constructed as a sequence of single-photon high-dimensional states
(qudits). A proof-of-principle implementation of the high-dimensional quantum
hashing protocol using orbital-angular momentum encoding of single photons is
implemented. It is shown that the number of qudits decreases with increase of
their dimension for an optimal ratio between collision probability and decoding
probability of the hash. Thus, increasing dimension of information carriers
makes quantum hashing with single photons more efficient.
