Quantum key distribution scheme with orthogonal product states - art. no. 042301

The general conditions for the orthogonal product states of the multistate systems to be used in quantum key distribution (QKD) are proposed, and a no vel QKD scheme with orthogonal product states in the 3 x 3 Hilbert space is presented. We show that this protocol has many distinct features such as g reat capacity and high efficiency. The generalization to n x n systems is a lso discussed and an asymptotic limit of 1/2 for the eavesdropper's success probability is obtained.