Abstract: Based on an identity based signcryption scheme proposed by Chen and Malone-Lee，an identity based proxy-signcryption scheme from pairings is proposed in this paper.The new scheme not only has the function of proxy signature scheme，but also has the advantage of identity based signcryption scheme.Only the intended recipient can recover the plaintext from the ciphertext，and the recipient can verify the validity of the proxy signature.As compared to the existing schemes，the new scheme provides both forward security and public verifiability.What’s more，the new scheme is more convenient for application.

Key words: proxy-signcryption, identity based cryptography, forward secure, bilinear pairings, signcryption

摘要： 借鉴Chen和Malone-Lee提出的基于身份的签密方案的思想，利用双线性对的特性构建出一个基于身份的代理签密方案。该方案既保持了基于身份签密的优点，又具有代理签名的功能，只有指定的接收者才能从密文中恢复消息，验证代理签名的有效性。与已有的方案相比，该方案同时具有前向安全性和公开验证性；并且新方案更适于应用。

关键词: 代理签密, 基于身份的密码, 前向安全, 双线性对, 签密