Research On Techniques Of Attribute-Based Encryption In Mobile Cloud Environment

With the popularity of mobile devices and the rapid development of 5G networks,mobile cloud computing models are recognized and respected by more and more people.The combination of mobile network and cloud computing gives people maximum freedom.It enables cloud computing to be greatly expanded in application scope.Users can get rid of the limitations of time and space and enjoy the powerful computing,storage and software services in the cloud.However,while cloud servers bring convenience to people,they also bring new security issues and challenges,such as data security and user information privacy protection.At the same time,in practical applications,the untrusted mobile cloud environment and the hardware limitations of the mobile terminal propose multiple scenarios and functional requirements for data sharing for multiple authorization mechanisms and revocables.How to ensure that data information is not leaked to unauthorized users and efficient sharing of data by multiple legitimate users in a mobile cloud environment becomes a problem that is solved and challenging.In view of the above challenges and problems,this paper designs a data security sharing scheme for mobile cloud environment based on attribute-based encryption technology to meet users' fine-grained access control and better user experience requirements during data sharing.And it has important theoretical significance and application value for realizing the secure,controlled,flexible and efficient sharing of mobile cloud data.The main research work is as follows:1.Aiming at the problem that the traditional ABE scheme based on bilinear mapping theory is less efficient and can not meet the requirements of mobile cloud configuration,an efficient multiinstitution attribute-based encryption scheme is proposed.Most of the proposed schemes are based on the ABE scheme of bilinear mapping technology,and the research is relatively deep,and the functional research is relatively mature.However,the efficiency of the solution is low,and the impact on mobile devices with limited computing power and communication bandwidth is particularly obvious,and it is not suitable for mobile cloud environments.In addition,in the multi-agency ABE scheme,the use of a secure channel by multiple organizations interacting with users and the cloud will also increase the computational and communication overhead of the mobile client.The scheme adopts the offline pre-calculation method in the encryption phase and the outsourcing method in the decryption phase to reduce the user's computational overhead;it is proved to be static and secure under the random prediction model.Data sharing in the mobile cloud environment can reduce the computing overhead of the mobile device by 20%,and better meet the low-configuration requirements of the mobile cloud environment for the user.2.Aiming at the diversified scenarios and functional requirements of data sharing for the untrusted mobile cloud environment and the hardware limitations of mobile terminals in practical applications,an attribute-based encryption scheme with no central multi-organization and user revocation is proposed.The scheme uses the mapping idea to construct a large attribute domain,and the total number of attributes does not have an upper limit;Without a central authority,each attribute institution can generate a private key independently from the user;Build an access structure based on a linear secret sharing scheme with a high degree of flexibility;Pre-computation is completed when the mobile terminal is offline,and the calculation is outsourced during decryption to reduce the user's calculation overhead;Under the random prediction model,the proof scheme is to support the user to revoke static security.To a certain extent,it enhances the practicability in the process of data sharing in the mobile cloud environment.3.ABE scheme based on bilinear mapping theory can't fundamentally solve the computational overhead problem caused by bilinear pairing,and it can't resist the problem of quantum cryptanalysis.A new multi-institutional attribute-based encryption scheme based on lattice theory for mobile cloud environment is proposed.The lattice theory is a new basic theoretical research method of attributebased encryption at the present stage,and it has a good performance in solving the anti-quantum problem.The scheme builds an access structure based on the extended linear secret sharing scheme based on the error learning difficulty assumption in the ideal lattice.The key distribution authority is used to distribute the key to meet the actual application scenario setting.Under the standard model,the scheme is adaptively selected to be clear-text safe.In contrast,the solution reduces the length of the system public key and can achieve the same user public key and cipher text length as the singleinstitution scenario,which is more in line with the actual application requirements of the mobile cloud environment.