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 electronicworld. Proxy signatures are signature schemes that an original signer delegates his signingcapability to a proxy signer, and the proxy signer creates signatures on behalf of the originalsigner. 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