抗主密钥泄露和连续泄露的双态仿射函数加密  

Master-Key Leakage-Resilient and Continue Leakage-Resilient Functional Encryption in Dual Affine Spaces

作　　者：张明武[1,2,3] 杨波[2] TAKAGI Tsuyoshi 

机构地区：[1]华南农业大学信息学院,广州510642 [2]陕西师范大学计算机学院,西安710072 [3]九州大学工业数学研究所,日本福冈819-0395

出　　处：《计算机学报》2012年第9期1856-1867,共12页Chinese Journal of Computers

基　　金：国家自然科学基金(60973134,61173164,61272404);广东省自然科学基金(10151064201000028);日本JSPS外国特别研究员项目(22-00045)资助~~

摘　　要：抗密钥泄露安全的加密系统保证在攻击者获得(主)密钥部分信息的情况下仍具有语义安全性.文中设计了一个抗密钥泄露的双态仿射函数加密方案,该方案中加密策略和解密角色定义为仿射空间,并且具有再次委托能力.在双系统加密模型下,实现了自适应安全的抗有界的主密钥泄露和用户密钥连续泄露的加密方案,在标准模型下基于静态子群判定假设证明了该方案的安全性.同时,分析了方案中的主密钥和用户密钥的泄露界和泄露率,通过参数调整可以达到接近73%的泄露率,具有较好的抗泄露性质.A leakage-resilient cryptosystem considers that an attacker is able to learn partial in- formation about some values used throughout the lifetime of the system. Leakage-resilient en- cryption guarantees that the scheme is semantically secure even though the attacker has the abili- ties in obtaining bounded private keys and/or master keys. In this paper, we propose a leakage- resilient functional encryption in dual affine spaces that encryption policies and decryption roles are specified as affine （sub）spaces. Also, both encryption policies and decryption roles can per- form delegation functionalities, which are flexible and expensive in practical applications. The proposed scheme can tolerant the bounded leakage in masters keys and private keys. We prove the security under the static subgroup decision assumptions in the standard model. Meanwhile, we analyze the tolerant bound and leakage ratio, and benefit the property of fine-grained leakage resilience.

关 键 词：函数加密 仿射空间 抗泄露 双系统加密 可证安全 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]