A Stydy Of Ciphertext Full-text Retrieval Research In Cloud Environment

With the coming of big data time,cloud storage technology has been rapid development and wide application. In the cloud storage environment, how to realize the huge amounts of data encryption storage, safe and efficient retrieval problems need to be optimized.The ciphertext full-text retrieval technologies is an important cross direction on research and application of cloud storage, full- text retrieval, information security in the cloud environment. In this paper, we deeply research on the full text search, searchable encryption and index structure based on B + tree technology conducted and carry out the following four aspects:Firstly, we propose a ciphertext full-text retrieval model based on cloud storage.To retrieval the large amounts of encrypt the information safe ly and effectively, we design a ciphertext full- text retrieval model based on cloud storage.O n this basis, we design a ciphertext full- text retrieval system, comprehensive analysis the threat of the system model, point out the direction of the ciphertext full-text index structure and the encryption scheme design.Secondly, we build a support ciphertext index structure of full-text retrieval. Based on inverted index and searchable encryption cipher, we construct the inverted index structure of the cipher text information retrieval.We establish B + tree index for vocabulary to further improve the retrieval efficiency.Thirdly, we design a cipher encryption scheme of full- text retrieval system.In order to guarantee the security of information, the content of the information for different adopted different encryption strategies The vocabulary of the index is encrypted by searchable encryption.The predicted machine model were used to certificate its safety.We use symmetric encryption to encrypt the original document to ensure the safety of the document.To improve the efficiency of key management,we use a multilevel key management strategy.Fourthly, we implement a ciphertext full text retrieval system.Based on the research of the above technology, we realize the core modules of the system.The index space, the construction of the index and keywords retrieval performance with other mainstream ciphertext full- text retrieval scheme are compared.Results show that the scheme on the index build takes longer than other schemes, but the logarithmic retrieval time superior to other solutions of linear search time.O ur system is more suitable for large data environment on the retrieval efficiency.