Designand Implementation Of Cross-Domaindigital Document Security Control System

Data reveal that leak of classified information has lead to great losses for enterprises and institutions. Most of traditional digital document security control systems are aiming at defending against external attacks, leaking from internal staff can’t be prevented. Digital document security control system focused on intranet security has become the hotspot and keystone of the researches on information secrecy.This paper conducted an investigation on existing digital document security control systems and found following two aspects of deficiencies:1. After publishing a document, the publisher has to transfer the file to recipient manually. This undoubtedly brings much inconvenience to the users, especially when softwares like QQ are not available on intranet.2. For existing systems, users can not access or use another independently deployed system, which will severely interrupt user’s regular work. To solve the problem of file transfer, a file transfer method based on IOCP is designed, implemented and deployed in digital document control system in this paper, so that the document will be transferred to the recipient’s client automatically after publish, significantly improving the user experience. This solution is implemented based on Winsock library, IOCP concurrency model with high performance, unique Bitmap structure and sliding window mechanism, it effectively solved the problem of file transferring.On the other hand, in order to enable users to access relatively independently deployed systems and perform cross-domain publish operation, this paper designed and implemented cross-domain access functionality and the synchronization of the user’s information between systems. A task management mechanism is designed to cooperate with the synchronization threads and schedule work according to the priority, retries of the failed work will be delayed.The Cross-domain Digital Document Security Control System this paper participates in, provides file transferring and cross-domain features, make up the shortcomings of existing similar products. The practical testing result of the system has showed the high reliability and low resources occupancy of the file transferring module and proved that the cross-domain feature can guarantee the synchronization of important information is given priority, complied with the design expectations.