Research On Novel Anti-Quantum Attribute Based Encryption Algorithms For Fog-Cloud Environment

Attribute based Encryption(ABE)is capable of controlling user's data access authority in fine-grained manner,which is very suitable for the complex and changeable data sharing scenarios in fog-cloud combination computing environment.Therefore,ABE scheme has become the most common fog-cloud data sharing encryption scheme.However,quantum algorithm that can quickly solve discrete logarithm problem has emerged.Thus,the existing ABE schemes are base on discrete logarithm problems,which are vulnerable under quantum algorithm attack.To maintain ABE scheme security in post-quantum era,lattice-based encryption algorithm are proposed and applied in ABE scheme.During the combination,it is important to imporve lattice-based encryption algorithm to realize fine-grained access control.Meanwhile,original security model of ABE scheme,called random oracle model,is not suitable for anti-quantum security.Hence,it is essential to apply mathematic reduction method to formally prove the security for ABE shceme with quantum algorithm attack resistance.Moreover,the existing ABE schemes are not implemented in fog and cloud computing environment.To meet the requirement of next generation mobile communications,lightweighted ABE shcemes are proposed for fog and cloud computing to provide uniform data sharing service for users in this two environment.Therefore,we propose three ABE schemes with quantum algorithm attack resistance for data sharing in cloud computing and fog-cloud computing.The proposed schemes can achieve fine-gained access control and secure data sharing with provable defense against quantum algorithm attack.The main contributions of this thesis are as follows.Firstly,we propose a revocable attribute-based encryption scheme,called RNL-ABE,based on NTRU lattice for cloud storage.In the RNL-ABE scheme,we combine encryption algorithm based on NTRU lattices with attribute-based encryption structure to resist quantum computing attacks and realize fine-grained access control and security attribute revocation to avoid keys re-distribution.Meanwhile,key structures are improved to defend collusion attack among legal users,revoked users and online intruders in RNL-ABE scheme.Finally,the quantum security of our RNL-ABE scheme was proved formally based on the learning with error problem over rings(R-LWE)under the selective-set model.In simulation comparison with other similar schemes,our RNL-ABE scheme shows advantages in efficiency.Secondly,we proposed a novel lattice based encryption scheme,called LBE-SAR,with secure attribute revocation for cloud storage.In our LBE-SAR scheme,we exploit improved trapdoor generator in key and ciphertext generation to withstand the quantum computing attack.Then we apply the imporved key and ciphertext components in attribute-based encryption scheme to realized secure attribute revocation.Meanwhile,we apply reduction of mathematics to formally prove that our LBE-SAR scheme can resist quantum attack and collusion attack based on the hardness of R-LWE problem.Finally,the high efficiency of our LBE-SAR scheme is demonstrated in performance simulation compared with other related works.Finally,we propose fine-grained data access and sharing scheme for a fog and cloud computing environment,called RABE-FCDS,basesd on R-LWE problem.We improve attribute-based encryption structure,define the concrete role of different parites in the scheme and realize fine-grained access control of encrypted data.Then we design key and ciphertext structure based on a novel lattice trapdoor and R-LWE problem to ensure the anti-quantum security of encryption.In addition,attribute revocation is secure and efficient for cloud users and fog users.The computation cost in RABE-FCDS scheme is more competitive compared with other similar schemes.