The Design And Implementation Of MFS-Based Campus Safety Synchronous Network Disk

Development of the Internet and the popularity of smart devices enable multiple computing terminals for each user. This has brought the need for file synchronization between multiple terminals and spawned a product named synchronous network disk. Synchronous network disk is a form of cloud storage application, the user can purchase storage space from the service provider or use some free storage space based on their requirements. They will be depositing their own data to the service provider, enjoying online data backup, sharing, synchronization of data between multiple terminals.For schools, on one hand, commercial products of synchronous network disk are usually based on public cloud storage which cannot be applied in some relatively closed campus network environment, on the other hand, synchronous network disk built on private cloud storage usually either is too expensive or the functionality is weak. The above mention solutions are unable to meet the needs of the campus environment.This paper analyzes the current synchronization network disk characteristics of the product, proposes an autonomous security synchronization network disk QXDrive based on a campus network application environment, and focuses on solving the two key technical issues of synchronization network disk as data synchronization and access control.The main contributions of this paper are as follows:Firstly, we constructed a general framework for synchronous network disk. This paper analyzes the synchronization network disk features and characteristics of on-campus network environment, the user needs for the synchronization network disk. We designed QXDrive store server in the client-server structure, including module functions at all levels and the relationship between modules.Secondly, we proposed a data synchronization algorithm named BDsync. In this paper, we defines the synchronization status, put the data synchronization problem into version control and differential transmission of two sub-problems. The synchronization algorithm BDsync uses timestamp for centralized version comparison; it uses version chain for conflict resolution and it uses optimized Rsync algorithm for data transmission. Experimental results show that the DBsync can satisfy the needs of synchronization network disk on version comparison and conflict management, the data transfer process compared with traditional Rsync algorithm has faster transmission speeds and lower cost of computing resources.Finally, we designed a ciphertext access control scheme for synchronous network disk. We proposed "honest but innocent" hypothesis for the credibility of school as a CSP base on the interests of the community relations between CSP and user on campus synchronous network disk. In the prgoram designed in this paper, CSP through RBAC control access permissions of data ciphertext, user through CCAC control decryption authority of ciphertext, this formed a ciphertext access control scheme, which jointly controlled by CSP and user. The implementation and analysis of this scheme shows that it can effectively prevent unauthorized users access to data on the campus network disk synchronization of data, thus providing an effective security protection.