双重系统加密研究: 获得完全安全的IBE及其扩展

双重系统加密技术首先由Waters提出,是用于构造完仝安全的基于身份的加密(IBE)及其扩展方案的有力方法.针对完全安全方案的构造,研究了双重系统加密技术并提出了一个完全安仝方案的通用构造方法,即将一个利用双重系统加密的IBE方案与一个普通的方案相结合,得到一个新的可以利用双重系统加密证明安全的方案.在通用构造的基础上提出了一个实例,该实例是一个基于层级身份的加密( HIBE)方案,具有常密文长度.该方案比Waters提出的双重系统加密HIBE方案更高效,并且在判定BDH假设和判定线性假设下证明是完全安全的.

Dual system encryption revisited: attaining fully secure identity-based encryption and its extensions

Dual system encryption was first proposed by Waters as a powerful method to prove full security for identity-based encryption(IBE) schemes and its extensions.To construct fully secure schemes,the application of dual system encryption is considered and a generic construction of fully secure schemes is presented.The construction combines a dual system encryption IBE scheme with a normal secure scheme and produces a new scheme which can be proven secure by dual system encryption.Based on the proposed generic construction,an instantiation,which is a hierarchical identity-based encryption(HIBE) scheme with constant ciphertext size,is presented.This scheme is more efficient than Waters’ original dual system encryption HIBE scheme,and it is proven fully secure under the Decision BDH and Decision Linear assumptions.