Abstract: In identity based cryptosystem, the user’s public key is bonded to user’s personal information, so it doesn’t need public key certificate, and improves the management efficiency. In the proxy signature, original signer’s signature right is transferred to proxy signer, thus theirself liberated from “trival” signature affairs. It proposes a new identity based proxy signature scheme and proves its security under the random oracle model. In the scheme, it needs 1 pairing in delegation of proxy right, 2 pairings in verification of proxy signature. Compared with the previous schemes, the efficiency is significantly improved.

Key words: identity-based cryptography, proxy signature, bilinear pairings, random oracle model

摘要： 基于身份的密码方案，将用户的公钥与用户的个人信息绑定，因此不再需要公钥证书，从而提高了管理效率。在代理签名中原始签名人可以将签名权利下放给代理签名人，从而将自己从“繁琐”的签名事务中解放出来。提出了一个新的基于身份的代理签名方案，并在随机预言模型下证明了其安全性。该方案在代理授权阶段只需要1次双线性对的计算，代理签名阶段也只需要2次双线性对计算，与以往方案比较，该方案在效率方面有显著提高。

关键词: 基于身份密码, 代理签名, 双线性对, 随机预言模型