中文摘要：

利用区块链技术实现的去中心化的密码货币被誉为有史以来最成功的密码货币。用户以公钥作为账户地址，使交易具备匿名性，即隐私的可保护性。然而区块链上记录的交易信息，会给用户隐私带来潜在的泄露威胁；此外，为了防止重复花费，系统约定只有在目标区块之后又有k个后续区块产生才能确认该目标区块上的交易是有效的，这段等待后续区块生成的时间较长，大大降低了交易效率。针对以上问题，提出一种基于代理的密码货币支付系统模型，并给出了基于盲签名算法的实现方案，通过在支付阶段引入代理，缩短了交易确认时间，提高了交易效率，同时，更好地实现了用户的匿名性即隐私保护功能。

英文摘要：

The decentralized cryptocurrency which was based on block chain has been thought the most successful one in history.In the system,public keys were used as the users’accounts which guaranteed the anonymity in real transactions.However,all the transaction information was recorded in the block chain,it was a potential threat for users’privacy which might leak the payment information.Moreover,to avoid double-spending,it was agreed that the transaction on the target block was valid only if another k blocks were generated after the target one.The long waiting time reduced the efficiency of the payment system.A model of payment system based on a proxy-cryptocurrency was proposed,and a solution based on blind signature techniques was proposed.The scheme introduced a proxy in the payment phase,by which transaction confirmation time could be reduced and the transaction efficiency could be improved.Meanwhile,the system implements better anonymity,namely as the privacy protection function.