标准模型下格上抗合谋攻击安全的代理重加密方案

摘要

The secure encryption schemes under the random oracle model can't be guaranteed their security in the real world,therefore,it has been a hot research topic to build a collusion resistant identity based proxy re-encryption scheme from lattices under the standard model.Based on the technologies of trap-generation function,left and right sampling and bit decomposition,a secure proxy re-encryption scheme with anti-collusion attack is designed under the standard model,whose security is proved to be based on LWE(learning with errors) hard assumption and can achieve IND-PrID-CPA security,in addition,the properties of unidirection,multi-hop and collusion-resistant security and other properties are also analyzed.%随机预言模型下安全的密码方案并不能保证在现实世界中的安全性,而构造标准模型下、基于格上困难问题,可抗合谋攻击的身份型代理重加密方案一直是密码学界的研究热点.通过采用陷门产生函数、左右抽样、bit分解等技术,设计了一个抗合谋攻击安全的基于身份代理重加密方案.在标准模型下,将该方案的安全性规约为判定性LWE(learning with errors)困难假设,证明了其能够达到IND-PrID-CPA安全,并对单向、多跳和抗合谋攻击等性质进行了分析.