一种消息保密的代理签名方案

为了保护原始签名人的隐私，提出了一种基于加密和盲签名的消息保密的代理签名方案。在代理授权过程中，原始签名人把消息用ElGamal算法加密后和其他代理授权参数一起传递给代理签名人；在代理签名过程中，签名接收人先解密消息，然后使用盲Nyberg Rueppel签名方案获得相应的代理签名。安全分析表明所提出的方案不仅满足代理签名的基本安全要求，而且能够保证除了指定的合法签名接收人外，包括代理签名人在内的其他人都无法了解消息的内容。

Digital proxy signature scheme with privacy protection

A proxy signature scheme based on encryption and blind signature was proposed to protect original signer's privacy. In delegation authorization, the original signer encrypts the message by ElGamal public-key cryptosystem and gives it with other delegating parameters to the proxy signer. In proxy signature generation, the receiver decrypts the encrypted message and then gets its proxy signature by Nyberg-Rueppel blind signature scheme.Security analysis shows that the proposed scheme not only meets the basic security requirements of proxy signature, but also ensures that the proxy signer and others except the valid receiver cannot get any information from the message.