论文部分内容阅读
鉴于基于身份加密方案(IBE方案)存在密钥托管问题,2007年Goyal创造性的提出了一种新的方法,即第三方权力受约束的基于身份加密方案(A-IBE方案),使得在一定程度上降低了用户对私钥生成方的信任需求.在Goyal的基础上,文中研究并提出了一种新的通用A-IBE方案.通过分析新方案的安全性证明可以看出:和Goyal的方案相比,新方案的安全性证明在一个更强的安全性定义(适应性选择挑战身份信息)下,基于一个更弱的难题(离散对数问题)实现了更“紧”的安全性规约.因此,相比Goyal的方案,新方案可以选择一个更小的安全参数,从而在一定程度上提高计算效率.在执行效率方面,新方案尽可能的减少了“对”运算的次数,且该次数达到最优,即不可能再减少该次数且不增加计算复杂性;在总的计算复杂度方面,新方案在相当的程度上比Goyal的方案更优.但遗憾的是,这些改进也会在一定程度上增加公开参数和通信量.因此实际应用中,可以选取折衷的或满足特定需求的公开参数的大小,进而平衡利弊.
In view of the key escrow problem with Identity Based Encryption (IBE), Goyal creatively proposed a new method in 2007, that is, the third-party power-based identity-based encryption scheme (A-IBE scheme) On the basis of Goyal, a new universal A-IBE scheme is researched and proposed in this paper.Through the analysis of the security proof of the new scheme, it can be seen that with Goyal’s scheme In contrast, the security of the new scheme proves more “tight” security based on a weaker problem (discrete logarithm problem) under a stronger definition of security (adaptive choice challenge identity information) Therefore, compared with Goyal’s scheme, the new scheme can select a smaller security parameter to improve computational efficiency to a certain extent.As far as the execution efficiency is concerned, the new scheme reduces the number of “” to "operations as much as possible , And the number of times is optimal, that is, it is impossible to reduce the number of times again without increasing the computational complexity; in terms of overall computational complexity, the new solution is rather superior to Goyal’s solution, but unfortunately, these Improvement will also be at a certain level Therefore, in practice, the size of public parameters that are eclectic or meet specific needs can be selected so as to balance the advantages and disadvantages.