Authority-based user authentication in quantum key distribution - art. no.022305

We propose secure protocols for user authenticated quantum key distribution on jammable public channels between two parties, Alice and Bob. Via an arb itrator, Trent, these protocols provide data integrity and mutual identific ation of the messenger and recipient. The first three are based on single-p hoton generation and detection. The first and second require (initially) an unjammable channel between the arbitrator and each party. The third requir es one broadcast from the arbitrator, disclosing what type of deterministic modification of the states sent through the quantum channel was done by hi m. The fourth and fifth protocols are based on two-particle entanglement wi th a preselection of nonorthogonal superpositions of Bell states. These two protocols also require one broadcast from the arbitrator disclosing the ty pe of entangled state in each sending.