Design And Implementation Of Secure File System In Cloud Computing

Cloud computing has realized people's dream of "computing as an infrastructure" for a long time.Based on cloud computing technology,cloud computing platforms can process tens of millions or even billions of information in seconds,thus providing information resources including computing,storage and broadband services to individual users and vendors through the Internet.This paper designs a cloud-oriented secure file system to provide users with a relatively secure and practical file access storage environment.The user types of the system can be divided into two categories: one is for individual users,the other is for group users.The file types stored on the system are from the point of view of encryption or not.It can be divided into plaintext file and ciphertext file.The two types of users can use the security access control module,searchable ciphertext module and trusted file transfer module to realize relatively safe file operation.The main contents of this paper include:(1)Design abundant file permission types and user access rules to restrict illegal users to access files,so as to achieve the role of file content protection.(2)The ciphertext strategy of access control system is adopted for ciphertext file.Only when the user's attribute set meets the access tree can the file be decrypted.Thus,the access control strategy determined by the data sender is realized.(3)For plaintext files,besides the precise query function based on keywords,TF-IDF algorithm and cosine similarity are used to calculate the similarity of this paper,and provide user similarity query.(4)Provide a keyword-based similarity query for ciphertext files.Users can execute similar queries before downloading and decrypting files,so as to improve the user experience.(5)Trusted File Transfer Module has done the following work: User A transmits files to User B,checking the integrity of the recipient files,so as to ensure that both users can confirm the consistency of file transfer.Finally,this paper implements a secure file system,and demonstrates the system through functional module demonstration and performance testing.