System for preventing access and expose documents in group

The present invention groups the leakage prevention for the document, and access control system for the security of the document group is started in. The system according to the invention, document security to store and manage user certificates, and in response to the user's registration request to perform a private key generation management, and support for time synchronization with the client when the viewing of documents, creation, modification and conversion server; A personal authentication information of the user certificate: that on the basis of (DN Distinguish Name) determines the license whether one of the document security server, and receives the time information and the private key synchronization on the basis of the permission to perform the encryption or decryption of the document the client terminal; And between the client terminal and the Document Security Server is configured as an Internet network tunnel for maintaining reliable communications infrastructure. Accordingly, the present invention, including the personal properties and personal log information, all in accordance with the managing the random key in a predetermined period based on the synchronization time information at the time of reading of a document, storage and a central information management system is introduced into companies and and blocking the malicious insider information leaked from the engine, there is an effect that can eliminate anxiety about the collaboration when information leakage as a third party. Online documentation, security, anti-leakage, time sync, view, create, edit, group