针对如何构造一个有效的抗量子攻击的类型代理重加密方案这个问题，对Zhang等人提出的格上基于身份的代理重加密方案进行分析，证明其存在私钥泄露和不能抗合谋攻击的问题；基于格上的LWE困难问题提出了第一个基于格的密文类型可以修改的类型代理重加密方案，其安全性可以规约为LWE困难性假设，并证明该方案是IND-CPA安全的。该方案不仅具有传统类型代理重加密方案的功能，而且可以抗量子攻击，密文的授权人可以随时修改密文的类型，具有更加广泛的应用场景。%In order to construct an efficient type-based proxy re-encryption scheme that can resist the quantum attack,this pa-per cryptanalyzed Zhang’s IBPRE scheme based on lattice,and shown that the scheme was vulnerable to collusion attack so that the private key was leaked.It presented the first dynamic type-based proxy re-encryption scheme based on lattice hard problem,whose security proved reduced to LWE assumption tightly.The construction was IND-CPA-secure cryptosystem.The scheme not only had the functions of the traditional type-based proxy re-encryption scheme,but also could resist the quantum attack,and the delegator of the ciphertext could modify the type of ciphertext dynamically.The proposed scheme is more use-ful in practical applications.
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