Unconditionally secure authentication for quantum key distribution

Abstract

This work describes the using of Universal and Strongly Universal classes of hash functions for unconditionally secure message authentication in quantum cryptogra- phy. Different classes are compared and constructions of flexible ε-Almost Strongly Universal classes are described. A new upper bound on the lifetime of a single hash function in one-time padded tags is introduced and optimisation on the final QKD key rate is shown for the QuAKE experiment, a B92 based QKD system. The public channel communication protocol of QuAKE is described, with special stress on the security issue