In response to the issue that semi-trusted nature of cloud servers in searchable encryption may result in incorrect or incomplete search results， a verifiable searchable encryption scheme of fine-grained result by designated tester in cloud was proposed. In this scheme， data users were allowed to query keywords on encrypted datasets to retrieve files， and verification mechanism was combined to ensure data privacy protection and reliability of search results in cloud； by introducing Merkle Hash Tree （MHT） with Rank value and Counting Bloom Filter （CBF）， correctness of dataset was verified， and accurate results were filtered out in a fine-grained way and the number of qualified files not returned was given， integrity of the dataset was ensured， dynamic updating of the dataset was implemented， and semantic security of selected keywords was proved under random oracle model. Simulation results demonstrate that compared to traditional certificateless verifiable search encryption schemes， the proposed scheme has lower computational overhead and higher execution efficiency in practical applications.

Based on the analysis concerning the drawbacks of applying RBAC, the concepts of context and rule were introduced, and the permissions were divided into enabled ones, active ones and limited ones, then a new access control model, the role and rule-based access control(RRBAC) model, was proposed. Through defining the security policy in design and capturing the corresponding contextual information in running, this model can provide finer access control, and reduce the workload of PA in the model of RBAC significantly.