基于纠缠交换的量子代理签名方案

A quantum proxy signature based on entanglement swapping

基于纠缠交换原理,提出一个量子代理签名方案.原始签名人对其手中的粒子进行Bell基测量,使得代理签名人的粒子和签名接收者的粒子纠缠起来,并将测量结果发给代理签名人完成授权.随后,代理签名人将待签消息按约定规则转化成量子态,联合手中分配粒子进行Bell测量完成签名,并将测量结果发给签名接收者.签名接收者根据签名信息与纠缠交换产生的关联,对手中的单粒子做相应的幺正操作恢复原始消息来完成验证.安全性分析证明方案满足不可伪造性、不可否认性等安全特性.方案中原始签名人制备的Bell态可循环利用,节约资源,且在当前实验技术条件下易于实现.

A quantum proxy signature scheme is proposed based on entanglement swapping.In this scheme,the original signer performs Bell-state measurements on her particles such that the proxy signer′s particles is entangled with the receiver′s particles.Then the original signer sends her measurement results to the proxy signer as part of her delegation certification.After-wards,the proxy signer measures his particles under the Bell-basis to complete his signature. According to the signature and the correlation of entanglement swapping,the receiver can re-construct the original message by performing appropriate unitary operations on his own parti-cles,then he can verify the proxy signature.Furthermore,the security analysis shows that the scheme satisfies the properties of unforgeability,undeniability and so on.After the original signer generates the Bell-states,it is no necessary to repeat it in later communications,so the entanglement resource is saved to a large extent.The proposed schemes can be implemented under the current laboratory techniques.