Research On Verifiable Secure Search In Cloud Computing

Cloud computing brings abundant benefits to our lives nowadays,including easy data access,flexible management,and cost saving.However,due to the concern for privacy,most of us are reluctant to use it.In order to protect user privacy and data security,before the user outsourcing data,first of all,the data is encrypted.Then,data owners outsource the encrypted data.However,it is a challenging problem for data users to effectively retrieve files of users' needs in encrypted data.On the other hand,the cloud server may return forged search results and incomplete search results,these lead cloud server to tamper with the data users' query results.Therefore,how to efficiently and safely verify the integrity of the query results is also a problem to be solved in this paper.The paper research how to verify the security search research around the cloud server,the work mainly includes the following two aspects.In the cloud computing environment,there are mainly some problems.They include low efficiency and accuracy of query.Moreover,all of the previous researches are based on a weak threat model,i.e.,they all assume the cloud to be"curious but honest".Different from the previous works,in this paper,we consider a more challenging model where the cloud server would probably be dishonest.Not only cloud server will leak user and data privacy in the query process,but also tampering with the query results.Therefore,based on the original MRSE scheme,this paper proposes a new PMRSETF scheme.We use the TF×IDF(Term Frequency-Inverse Document Frequency)to replace keyword of bloom filter in the original scheme.At the same time,the index vector is extended to N dimension and added to the interference factors for the security of the query process.Finally,by doing extensive experiments,based on the "dishonest" cloud server,we confirm that our proposed schemes can work efficiently and improve the security.Based on the "dishonest" cloud server model,the paper further verifies the integrity of the multi-keyword ranked query results.First of all,we use the privacy preserving order function to encode the file vectors.Then,the encoded file vectors are sorted.Based on the ranked encoded vectors,we design a novel Multi-Attribute Authentication Tree(MAAT)to verify the dynamic top-k search results.Simultaneously,there is the problem of efficiency,when the file keywords are too much.Therefore,we propose an optimization scheme by using the entropy to quality privacy to reduce the size of verification objects so that the communication cost between the cloud and data users is tunable.Finally,by doing extensive experiments,we confirm that our proposed schemes can work efficiently.