关键词: 代理签名, 指定接收人, 合谋攻击, 可跟踪性

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