Quantum cryptography on multi-user network architectures
Patrick D. Kumavor, Alan C. Beal, Susanne F. Yelin, Eric S. Donkor, Bing C. Wang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2006
Quantum cryptography applies the uncertainty principle and the no-cloning theorem to allow to parties to share a secret key over an ultra-secure link. Present quantum cryptography technologies provide encryption key distribution only between two users. However, practical implementations of encryption key distribution schemes require establishing secure quantum communications amongst multiple users. This paper looks at some of the advantages and drawbacks of some common network topologies that could be used in sending cryptographic keys across a network consisting of multiple users. These topologies are the star, ring, and bus networks. Their performances are compared and analyzed using quantum bit error rate analysis. The paper also presents an experimental demonstration of a six-user quantum key distribution network implemented on a bus topology.