基于格的访问控制加密技术研究OACSTPCD

Access Control Encryption is a novel public-key encryption concept.It can not only protect the confidentiality of data,but also realize the control of information direction.The early scheme based on the DDH(decisional Diffie-Hellman)assumption suffers from the ciphertext leakage attack and only satisfies the chosen plaintext attack(CPA)security.For such problems,cryptologists proposed a security definition of the chosen ciphertext attack(CCA)and constructed a CCA security scheme based on Naor-Yung construction strategy.However,cryptologists have not fixed the security flaw of the DDH scheme,and their CCA scheme has shortcomings such as the low efficiency,complex construction and limited communication strategy.In this paper,the DDH scheme is designed generically,and the flaw of the DDH scheme subjected to the ciphertext leakage attack is remedied in an efficient way.Furthermore,a CCA secure access control encryption scheme is constructed,which is efficient,simple in design and based on the standard difficulty assumption.Finally,based on the lattice difficulty assumption and the decisional bilinear Diffie-Hellman(DBDH)assumption respectively,two kinds of CCA security schemes are instantiated.