Multi‐stage quantum secure communication using polarization hopping

Abstract

AbstractThis paper proposes a generalized multi‐stage multi‐photon protocol that uses arbitrary polarization states to securely communicate between a sender and a receiver. Because the polarization measurement of an arbitrarily polarized state results in altering the state in an irreversible way, any such measurement produces noise in the measured state. The proposed multi‐stage protocol exploits this phenomenon to provide quantum secure communication. This paper assesses the vulnerability of the multi‐stage protocol to photon number splitting attack and Trojan horse attack. In addition, it presents an upper bound on the number of photons that can be used per pulse to exchange information while maintaining quantum‐level security. Determination of such a bound is important for the multi‐stage protocol to operate in the multi‐photon domain while maintaining a quantum level of security. Furthermore, this paper proposes a key/message expansion scheme that provides another layer of security to the multi‐stage protocol. The multi‐stage protocol, can potentially provide higher data rates as well as longer communication distances. Copyright © 2015 John Wiley & Sons, Ltd.