A Robust Self-Synchronized Quantum Key Distribution Protocol

Quantum key distribution (QKD) is well known toward absolute communication security to distribute the keys of one-time pad cryptographic mechanisms, given the assumption of an error-free quantum channel. To explore the engineering practice of QKD, we consider an imperfect quantum channel and propose a robust self-synchronized QKD (SSQKD) protocol. By expanding the well known BB84 4-state QKD system to a 6-state protocol, the additional signal space is used for non-sacrificial detection and self-synchronized channel estimation. Performance evaluation verifies the effectiveness of this proposed SSQKD against phase-distortion in the quantum channel.