结合格上的困难问题对基于身份的分层加密(HIBE)体制进行分析与研究.针对现存方案公钥长度大、密文扩展率高的缺陷,对理想格上的陷门产生函数算法进行改进,并以新的陷门作为私钥提取算法的输入,生成用户的私钥,实现消息的加解密,从而基于判定性R-LWE(learning with errors over ring)困难问题构造了一个高效安全的HIBE方案,对它的安全性以及效率进行了分析.分析表明,本文提出的方案效率较高,且能够实现较高的安全性.
Lattice-based cryptography with a superior and efficient algebraic structure becomes a hot topic.In this paper,combining with the difficult problems based on lattice,we make a research on hierarchical identity-based encryption(HIBE)cryptosystems.To solve the problems of big public key and high expansibility rate,we improve the trapdoor function on the ideal lattice,which is regarded as the key component of our private key generation procedure.And then,we propose a new HIBE scheme based on learning with errors over ring(RLWE).Finally,we analyze the security and efficiency,and the result shows our scheme is more efficient and safe.