标准模型下一种实用的和可证明安全的IBE方案  

An Efficient and Provably Secure IBE Scheme Under The Standard Model

作　　者：徐鹏[1] 崔国华[1] 雷凤宇[1] 汤学明[1] 陈晶[2] 

机构地区：[1]华中科技大学计算机科学与技术学院信息安全实验室,武汉430074 [2]武汉大学计算机学院,武汉430072

出　　处：《计算机学报》2010年第2期335-344,共10页Chinese Journal of Computers

基　　金：国家自然科学基金(60703048);国家青年自然科学基金(60903196);湖北省自然科学基金(2007ABA313,2009CDB379)资助

摘　　要：组合公钥方案是一种用于基于身份密码体制中生成用户加密密钥和私钥的知名方案.针对组合公钥方案存在合谋攻击的问题,通过仅扩展该方案的私钥生成过程,实现了扩展方案的抗合谋攻击性.在此基础上构建标准模型下基于Decisional Bilinear Diffie-Hell man假设可证明安全的一种新的基于身份加密方案.最后,为了说明所构新方案的实用性,分析了扩展组合公钥方案的用户加密密钥抗碰撞性;对比了新方案和同类的3个知名方案在安全性证明的归约程度方面、加解密的时间复杂度方面和密文的长度方面的性能,表明了新方案在以上3点上具有目前最优的指标.因此新方案是相对较实用的.The Combined Public-Key scheme is a famous scheme which is commonly used to generate user＇s encryption-key and private-key in the identity-based encryption schemes. For over- coming the conspiracy attack on Combined Public-Key scheme, a new expanded scheme based on it is proposed in which the generation of private-key is an expansion of the corresponding part of combined public-key scheme. Based on the new expanded Combined Public-Key scheme, a new identity-based encryption scheme is proposed, and under the standard model it is provably secure based on Decisional Bilinear Diffie-Hellman Assumption. At last, by analyzing the collision of user＇s encryption-key and comparing the new proposed identity-based encryption scheme with three existed famously analogous schemes at the following three aspects： the tightness of reduc- tion in security proof, the complexity of encryption and decryption and the binary length of ciphertext, it can be found that the new scheme is more efficient than them, so it is comparatively more useful.

关 键 词：组合公钥 合谋攻击 标准模型 Decisional BILINEAR DIFFIE-HELLMAN假设 基于身份加密 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]