Research On Searchable Encryption Scheme In Cloud Storage Environment

With the popularity of cloud storage,users' local storage have not met the need of users' bulk storage.Therefore,more and more users choose data cloud,that is,to store files into cloud server.But,data are stored in clear text.Problems of leaking data emerge;However,If data are stored in ciphertext,they can not be search out on cloud servers.Searchable encryption technology can make users store data into cloud servers in ciphertext but cloud servers can search these data-ciphered,which can save the room of local storage and secure privacy of data further.As for searchable encryption service,if use only one cloud server to not only save data-ciphered but also search those data,then the cloud server have to be endowed more rights or power to make cloud server exert guessing attack on data-ciphered.Multi-servers models can carry out the task of storage and search on different servers.Therefore,using several servers can avoid guessing attacks and elevate the efficiency of search.Key aggregation technology can merge several keys into one key so users can use the key to decode different files in one document.This paper is based on some traits of certificateless public key cryptosystem,multi-servers,key aggregation to research searchable encryption scheme on occasions of multiservers,keys aggregation and verification.(I)Design a searchable encryption scheme characterized by multiservers without certification.To avoid a single server that carry out overtasks,influence storage and effectiveness of search,put forward a searchable encryption scheme characterized by multiservers.The two task of storing data and search trapdoor are carried out by different servers so that we can elevate data search efficiency and security.Meanwhile,under the model of random oracle,it is proved that the attack against two types of adversaries satisfies the trapdoor indistinguishable security.(II)In order to solve the problem that the number of keys held by users increases with the number of retrieved documents,combined with the characteristics of multi-servers,a multi-server searchable encryption scheme with key aggregation is designed under the certificateless system.In the scheme,users can decrypt different files in the same document by using the aggregated key,thus reducing the problem of key management.(III)In the industrial Internet of things environment,based on the certificateless cryptosystem,a verifiable searchable encryption scheme is proposed.This scheme add the authentication problem for data owners and users,which can not only prevent data owners from denying the uploaded ciphertext,but also prevent malicious users from generating keyword search credentials by pretending to be real users,then get the corresponding ciphertext.