A data destruction model based on lifecycle control under cloud storage environment was proposed to solve the lack of effective data destruction mechanism for user data, and that data security was threatened and destruction time was controlled in the life cycle, which greatly limited the development of cloud services. The plain text was processed by functional transformation to generate the cipher text and metadata and avoid the complex key management. Secondly, in order to improve the controllability of data destruction, a self-destruction data objects based on controllable time was designed, which made any illegal access of expired objects to trigger the assured deletion by rewriting program, and realized the data destruction based on lifecycle control. The analysis and experimental results show that the scheme can enhance the flexibility and controllability of data destruction and reduce the performance cost, while protecting the data safely and effectively.

Aiming at the replication consistency maintenance problem of cache in publish/subscribe systems, firstly, a new algorithm based on trace label was proposed to improve the consistency maintenance algorithm based on gossip. The trajectory information of nodes was added to update information message, which avoided sending redundant update messages to updated nodes. Secondly, in order to improve the reliability of message propagation, a hierarchical feedback recovery mechanism based on trajectory label was proposed, which combined push/pull transmission mode of publish/subscribe systems, reduced the number of feedback messages, and avoided feedback implosion. The simulation experimental results show that the improved consistency maintenance algorithm can reduce the message cost and time cost of the consistency maintenance, and improve the system's reliability and scalability.