A security proof of the round-robin differential phase shift quantum key distribution protocol based on the signal disturbance. (25th May 2017)

• Record Type: Journal Article
• Authors: Sasaki, Toshihiko; Koashi, Masato
• Is Part Of: Quantum science and technology. Volume 2:Number 2(2017)
• Publication Date: 2017-05-25
• Subjects: round-robin differential phase shift quantum key distribution protocol -- quantum key distribution -- quantum cryptography; Quantum theory -- Periodicals; Quantum theory; Periodicals; 530
• DOI: 10.1088/2058-9565/aa6ef9
• Languages: English
• ISSNs: 2058-9565

Abstract

Abstract: The round-robin differential phase shift (RRDPS) quantum key distribution (QKD) protocol is a unique QKD protocol whose security has not been understood through an information-disturbance trade-off relation, and a sufficient amount of privacy amplification was given independently of signal disturbance. Here, we discuss the security of the RRDPS protocol in the asymptotic regime when a good estimate of the bit error rate is available as a measure of signal disturbance. The uniqueness of the RRDPS protocol shows up as a peculiar form of information-disturbance trade-off curve. When the length of a block of pulses used for encoding and the signal disturbance are both small, it provides a significantly better key rate than that from the original security proof. On the other hand, when the block length is large, the use of the signal disturbance makes little improvement in the key rate. Our analysis will bridge a gap between the RRDPS protocol and the conventional QKD protocols.