The Design And Implementation Of Encrypted File System Server-side In Android

With the development of computer technology, more and more people store kinds ofinformation into electronic documents rather than paper documents. Storing Data in thecomputer is helpful to save space, and allows people to find and read the information fasterand more convenient, but this also poses a serious problem of information security. If theinformation stored on portable devices such as notebook computers are accessed illegally toor destructed, a huge loss will be given to its owner. Therefore, how to ensure the safety of thefile data, and how to minimize the losses caused by the missing files has become an importantresearch topic.This paper discusses the design and implementation of a auditing and encryption filesystem server-side. This file system is based on the Internet. We choose Android mobilephone system which is announced by Google as the server, the reason why we choose it is thatcell phone communications become more and more popular, people can make use of wifisoftware to access internet. The feature of the portable devices is mobility, we can surferinternet when there is symbol everywhere with the smart phone, it solves the problem that wecant’t access internet when fixed network is not available. Users’ personal information isstored in a unified server. To access to the client file system, users must enter their user nameand password. Files stored in the client file system needs to be encrypted by different fileencryption keys, which are stored in the server. Before accessing encrypted files, users mustobtain the corresponding file key to decrypt the file after the authentication. In order to ensurefile integrity, a summary of the contents of the file will be sent to the server-side and validated.The server logs will record all file operations. If the device is lost, users can log on to theserver to report the loss. Then the server will stop all activities carried out in the accounts.Users can know the condition of the leak of information and take certain remedial measures.Based on FUSE framework and the Blowfish encryption algorithm, we achieve a Linuxuser-space file system to avoid modifying the kernel, and make the system more stable. At thesame time, the FUSE framework allows users to access files transparently. Users can not feelthe presence of the encrypted file system.At the end of this paper, the functionality and performance of the file system is tested.The results show that the file system meets the design requirements proposed in this paper.