电子世界中,签名权力的委托通过代理签名来解决。代理签名是原始签名者将他的 签名权委托给代理签名者的一种签名体制,代理签名者代表原始签名者进行签名。2002 年,K.Shum 和 K.Wei 提出的体制中,可以隐藏代理者的身份。如果仅仅通过代理签名,没有人能够确定代理签名者的身份。而且,如果必要的话,可信任机构可以揭示代理签名者的身份。然而,Narn-Yih Lee 指出K.Shum 的签名体制不满足强不可否认性。最后,我们提出一种代理签名体制,这种签名体制能克服以上指出的弱点。新体制满足强不可否认性。 关键词: 签名;秘密;代理签名;安全 Abstract: Proxy signature is the solution to delegation of signing capabilities in electronic world. Proxy signatures are signature schemes that an original signer delegates his signing capability to a proxy signer, and the proxy signer creates signatures on behalf of the original signer. In 2002, K.Shum and K.Wei presented a scheme to hide the identity of the proxy signer. No one can determine the identity of the proxy signer only from the proxy signature. Moreover, a trusted authority can reveal the proxy signer’s identity if needed. However, Narn-Yih Lee points out that the K.Shum and K.Wei’s scheme cannot keep the property of the strong unforgeability. Finally we present a proxy signature schemes which overcome the weakness mentioned above. That is, new scheme can keep the property of the strong unforgeability. Key words: signature; privacy; proxy signature; security