Abstract: To satisfy the original signer hope，a threshold proxy signature scheme is proposed with designated receiver.The original signer nominates a receiver of proxy signature during the generation process of delegation parameters.When he delegates his signing power to a proxy signer，the proxy signer generates proxy signature on behalf of him by the nominative signature scheme.It satisfies the basic security requirements of proxy signature：The identity of the proxy signer can not be known at the same time；when disputation appears，the original signer can reveal the real identity of the proxy signer with the help of the GP；furthermore，the valid proxy signature generated by the proxy signer on behalf of the original signer can only be verified and thus accepted by the receiver nominated by the original signer.

Key words: proxy signature, designated receiver, conspiracy attack, traceability

摘要： 为了满足原始签名人的意愿，提出一个指定接收人的门限代理签名方案。在代理授权的过程中，原始签名人通过授权指定代理签名的接收人，代理签名人在验证原始签名人所提供的授权参数合法的基础上产生代理签名密钥，从而可以产生代理签名。提出的签名方案具有代理签名方案的基本安全要求：不仅验证人在验证代理签名之后只能确信代理签名是代表原始签名人的签名而无法确定代理签名者身份；当出现争议时，原始签名人可通过代理群管理员追查出代理签名人的身份；而且保证代理签名人只能对所指定的签名接收人产生代表原始签名人的有效代理签名，从而防止了代理签名权利的滥用。

关键词: 代理签名, 指定接收人, 合谋攻击, 可跟踪性