| Attribute based encryption schemes have the feature of "one to many" encryption,which allows access control to users through their own attributes,with a control granularity of attribute level.It has a broad application prospect in the Internet of Things environment.Traditional attribute based encryption schemes have high computational overhead,while most terminal devices in the Internet of Things have weak computing power,making it difficult for traditional attribute based encryption schemes to be directly applied in the Internet of Things environment.Therefore,it is necessary to improve the traditional attribute based encryption scheme,improve the execution efficiency of the scheme while ensuring security,and make it suitable for the application environment of the Internet of Things.Based on the security and efficiency requirements of the Internet of Things environment,this article conducts research on attribute based encryption schemes that support key traceability and user attribute revocation,and reduces the execution cost of the scheme by outsourcing complex computing.This thesis first proposes a lightweight attribute based encryption scheme that supports key traceability for data security protection of the Internet of Vehicles system in autonomous driving.In order to reduce the computational overhead of the scheme,offline encryption and outsourcing decryption are adopted,and partial identity information is embedded in the key to achieve key traceability.In order to improve the flexibility of the application of the scheme and support the dynamic joining and exiting of users,this thesis further proposes a lightweight attribute based encryption scheme that supports user revocation.By introducing a short signature,authorities can set a time limit for users to access data,thereby achieving indirect revocation of dishonest users.The scheme also uses a Linear Integer Secret Sharing(LISS)scheme to enable the data owner to directly provide a user revocation list when encrypting,to avoid malicious users accessing data.While optimizing the access structure,it implements the encryptor’s direct revocation function for users.This scheme reduces the computational overhead of data users by outsourcing decryption calculations.This thesis theoretically analyzes the proposed lightweight key tracing scheme and user revocation attribute based encryption scheme,and provides the correctness and security proof of the scheme based on the security model.In terms of performance analysis of the scheme,through comparison with experimental simulations of similar schemes,the proposed scheme in this thesis has a certain improvement in performance,which can effectively solve the problem of low computing power of devices in the Internet of Things environment,and better meet the application requirements of the Internet of Things environment. |
