Research And Application Of Attribute-based Cryptography Scheme With Special Properties

Attribute-based encryption is a hot direction in the research of public key cryptography,which is widely used because of its advantages of fine-grained access control.According to the different access control requirements,it is necessary to construct attribute-based cryptographic schemes with different properties,such as access control in multi-user environment,identity authentication,attribute revocation,multi-authorization agencies and so on.This paper studies the attribute-based cryptographic scheme with special properties,and the main work is as follows:(1)User attribute revocation is one of the characteristics of attribute-based encryption scheme,the direct revocation mode of attribute is more effective than indirect revocation,it is relatively easy to construct attribute direct revocation scheme under KP-ABE,and it is more complicated to construct attribute direct revocation scheme under CP-ABE.In order to solve the above problems,an attribute-based encryption scheme supporting attribute direct revocation is constructed in multi-institutions.The scheme realizes the direct revocation of attributes in CP-ABE and KP-ABE modes,at the same time,there is no need to update the user key,and the user does not bear the re-encryption work caused by the ciphertext update.(2)In the multi-user application environment,the simple use of user private key to achieve identity authentication is too simple to meet the fine-grained access control needs of users,and there is a complex user key management situation.In order to solve the above problems,a traceable revocable attribute-based authentication scheme is constructed based on linear code,in which revocation list is used to manage attribute revocation.When there is a key abuse or a denial of service attack on the system,the true identity of the malicious user can be tracked according to the signature.Finally,under the MBDH problem,it is proved that the scheme satisfies the existence of unforgeability,and the performance comparison and numerical analysis show that the scheme has shorter key length and less computational overhead.(3)The popularity of 5G mobile network improves the data transmission rate to a great extent,but for the mobile terminal devices with limited resources in the network,it is difficult to bear the high computing overhead caused by attribute-based encryption in communication.To solve this problem,an online / offline attribute-based encryption scheme for 5G mobile networks is proposed.The idea of hybrid encryption is adopted to deal with the ciphertext and the key respectively,and the online / offline technology is used to reduce the computing overhead at the same time in the encryption and decryption phase.It is proved that the scheme is secure under the difficult problem of determining q-parallel BDHE.Numerical analysis shows that the scheme has less computational overhead and can achieve fine-grained access control of user decryption rights.