Inventors:
Howard E. Brandt - Silver Spring MD
John M. Myers - Boston MA
Assignee:
The United States of America as represented by the Secretary of the Army - Washington DC
International Classification:
H04B 1000, H04K 102, H04L 900
Abstract:
Quantum key distribution (QKD) employs non-orthogonal quantum states to distribute a random bit sequence between two users for use as a provably secure key for encryption and authentication. The key generation procedure involves the transmission, interception, and reception of two nonorthogonal photon polarization states. At the receiving end, a positive-operator-valued measure (POVM) is employed in the measurement process. The invention is a receiver that is an all-optical realization of the POVM and includes a Wollaston prism, a mirror, two beam splitters, a polarization rotator, and three photodetectors.