電子世界中，簽名權力的委托通過代理簽名來解決。代理簽名是原始簽名者將他的
簽名權委托給代理簽名者的一種簽名體制，代理簽名者代表原始簽名者進行簽名。2002 年，K.Shum 和 K.Wei 提出的體制中，可以隱藏代理者的身份。如果僅僅通過代理簽名，沒有人能夠確定代理簽名者的身份。而且，如果必要的話，可信任機構可以揭示代理簽名者的身份。然而，Narn-Yih Lee 指出K.Shum 的簽名體制不滿足強不可否認性。最后，我們提出一種代理簽名體制，這種簽名體制能克服以上指出的弱點。新體制滿足強不可否認性。
關鍵詞: 簽名；秘密；代理簽名；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