B92量子密钥分配协议的变形及其无条件安全性证明

Modification of B92 protocol and the proof of its unconditional security

分析了Shor和Preskill证明BB84量子密钥分配协议无条件安全性的方法 ,指出不能用Shor Preskill方法直接证明B92量子密钥分配协议的无条件安全性。同时借鉴Shor Preskill方法 ,引入一种将B92协议转化为BB84协议的变换 ,通过证明该变换过程不会泄漏密钥信息给窃听者 ,以此证明B92协议的无条件安全性 .也解决了Lo等人提出的关于用Shor Preskill方法证明B92协议的困难 .

Shor and Preskill's method with which thy proved the unconditional security of BB84 quantum key distribution protocol was analyzed first. We also indicated that their method could not be applied to prove the unconditional security of B92 scheme directly. In order to take advantage of Shor Preskill's techniques in their proof of the unconditional security of BB84, we have introduced in this paper a transformation that can exchange between BB84 and B92. By proving that the transformed B92 protocol leaks no more information to eavesdropper, we demonstrate the unconditional security of B92. We also solve the problem how to prove the unconditional security of B92 with Shor Preskill's method.