摘要： 代理签名与指定验证人签名都是非常有用的密码学工具，在实际生活中有着广泛的应用。在代理签名中，原始签名人能将数字签名的权力委托给代理签名人；而在指定验证人签名方案中，对于验证人是有所限制的。该文结合二者的优点，利用基于离散对数的Schnorr数字签名方案构造了一个指定验证人的代理签名方案。新提出的方案能够满足代理签名和指定验证人签名的安全性质。分析显示，新方案不仅是安全的，而且在通信和计算方面是高效的。

关键词: 代理签名, 指定验证人签名, 数字产品, 电子商务, 信息安全

Abstract: Proxy signature and designated-verifier signature are useful tools in cryptography. They both have wide applications in real life. In a proxy signature, an original signer can delegate his signing power to a proxy signer who signs a message on behalf of the original signer. In a designated-verifier signature the verifier is restrictive. The characteristics of proxy signatures and designated-verifier signatures are combined. Using the schnorr signature scheme based on DLP, a designated-verifier proxy signature scheme is presented. The new scheme satisfies the security properties of both proxy signature schemes and designated-verifier signature schemes. Analysis shows that the new scheme is secure and efficient in computation and communication.

Key words: Proxy signature, Designated-verifier signature, Digital product, E-commerce, Information security