Wen Kai, Tamaki Kiyoshi, Yamamoto Yoshihisa
Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2009 Oct 23;103(17):170503. doi: 10.1103/PhysRevLett.103.170503. Epub 2009 Oct 22.
In this Letter, we prove the unconditional security of the 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 the DPS-QKD protocol can generate an 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 a coherent state DPS-QKD.
在本信函中，我们基于将其转换为等效的基于纠缠的协议，证明了单光子差分相移量子密钥分发（DPS-QKD）协议的无条件安全性。我们从误码率估计相位误差率的上限，并表明当误码率不大于4.12%时，DPS-QKD协议能够生成无条件安全的密钥。这一证明是相干态DPS-QKD无条件安全性证明的第一步。
