Unconditional Security of Single-Photon Differential Phase Shift Quantum Key Distribution
arXiv:0806.2684 · doi:10.1103/PhysRevLett.103.170503
Abstract
In this Letter, we prove the unconditional security of single-photon differential phase shift quantum key distribution (DPS-QKD) protocol, based on the conversion to an equivalent entanglement-based protocol. We estimate the upper bound of the phase error rate from the bit error rate, and show that DPS-QKD can generate unconditionally secure key when the bit error rate is not greater than 4.12%. This proof is the first step to the unconditional security proof of coherent state DPS-QKD.
5 pages, 2 figures; shorten the length, improve clarity, and correct typos; accepted for publication in Physical Review Letters