NTRU格上高效的基于身份的全同态加密体制  

Efficient identity-based fully homomorphic encryption over NTRU

作　　者：段然 顾纯祥[1,2] 祝跃飞 郑永辉[1,2] 陈莉[3] 

机构地区：[1]信息工程大学四院,河南郑州450002 [2]数学工程与先进计算国家重点实验室,江苏无锡214125 [3]河南财经政法大学网络信息安全研究所,河南郑州450046

出　　处：《通信学报》2017年第1期66-75,共10页Journal on Communications

基　　金：国家科技支撑计划基金资助项目(No.2012BAH47B01);国家自然科学基金资助项目(No.61170234;No.61309007;No.61502533);河南省科技创新杰出青年基金资助项目(No.134100510002);河南省基础与前沿技术研究基金资助项目(No.142300410002);河南省高校科技创新人才支持计划基金资助项目(No.13HASTIT043)~~

摘　　要：全同态加密是目前解决云计算网络数据隐私保护问题的最佳方案,但目前的体制的公钥尺寸普遍较大。首先,通过引入Kullback-Leibler散度的概念,构造一种NTRU格上的基于身份公钥的加密体制,参数分析表明体制具有较小的密钥和密文尺寸,实验数据表明体制具有较高的加解密效率。其次,利用近似特征向量技术,给出一种方法,将基于身份的公钥加密体制转换为基于身份的全同态加密体制,可以进一步减小密文尺寸。和现有体制相比,除了不需要计算密钥,实现真正意义上的基于身份特性以外,还减小了密钥和密文尺寸,提高了计算和传输效率。Fully homomorphic encryption is the best solution for solving privacy concerns for data over cloud so far, while large public key size is a general shortcoming for existing schemes. First, by introducing the concept of Kull- back-Leibler divergence, an identity-based public key scheme over NTRU lattice with modified ciphertext form was proposed. Analysis on parameter setting showed its small key size and ciphertext size, and experiments revealed its high computational efficiency. Second, with the idea of approximate eigenvector, an improved method to convert the scheme into an identity-based fully homomorphic encryption one was put forward to further reduce ciphertext size. Compared with existing schemes, the converted scheme not only abandons evaluation keys to make it fully identity-based, but also has smaller keys and ciphertext, which results in higher computational and transmission efficiency.

关 键 词：全同态加密 基于身份加密 NTRU格 随机谕示模型 近似特征向量 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]