摘要： SAKI方案可以有效解决基于身份的密码体制中用户如何向私钥产生中心证明自己的身份并安全得到其产生的用户私钥这2个问题，但其存在安全缺陷。针对上述情况，提出改进的方案。对比分析结果证明，改进的方案在保留SAKI方案简单、高效等优点的同时，可以抵抗口令的字典攻击、偷取认证攻击、中间人攻击和私钥申请报文完整性攻击。

关键词: 基于身份, SAKI方案, 双线性对, 超奇异椭圆曲线

Abstract: Separable and Anonymous identitybased Key Issuing(SAKI) scheme can solve the problems that how to authenticate the user’s identity and distribute the user’s private key in identitybased cryptography, but it has secure flaws. This paper investigates the secure flaws of SAKI scheme and proposes an improved scheme. Comparison analysis result shows that the improved scheme keeps simplicity and high efficiency of SAKI, and can resist keyword dictionary attack, stolen verifier attack, maninmiddle attack and privacy key integrality attack.

Key words: identitybased, Separable and Anonymous identitybased Key Issuing(SAKI) scheme, bilinear pairing, supersingular elliptic curve

中图分类号: 

• TP309