Research On Strong Forward And Backward Secure Dynamic Searchable Symmetric Encryption

With the development and application of keyword search on the encrypted database,research on searchable encryption is significant in the practical application,achieving holding data and providing the search function in the untrusted cloud server.The dynamic searchable symmetric encryption not only supports keyword search in the untrusted cloud server,but also supports entity update including addition and deletion in the database.Most of the existing schemes concern the leakage about single operation.For the leakage of multiple operations,only the forward and backward security is defined to guarantee that the added file cannot be linked to the before keyword search query and the deleted file cannot be linked to the later keyword search query.However,the forward and backward security cannot resist the non-adaptive file injection attack,count attack,leakage-abused attack thoroughly.Therefore,the attacks based on the information leakage from multiple operations is a focus.The paper proposes “strong forward and backward security” and concern strong forward and backward secure dynamic searchable symmetric encryption.The paper considers on the leakages of access pattern,search pattern and size pattern,and then resists the attacks based on the information leakage from multiple operations by breaking three kinds of linkability such as search-search linkability,search-update linkability and update-update linkability.That is to say,breaking all the links during the search and update queries can efficiently resist the attacks.To protect the strong forward and backward security,this paper prompts two specific schemes of multiserver dynamic searchable symmetric encryption,one scheme allowing some servers to coalition,and the other allowing no server to collude.In this paper,we use the ability of secure multi-party computation and efficient communication between the cloud servers to improve the response time of dynamic searchable symmetric encryption scheme.The design of novel server-side can simply the update operation,improve the security degree and achieve the strong forward and backward security.