Method of protecting digital information and system thereof

PURPOSE: A method for securing digital information and a system thereof are provided to prevent an internal illegal usage for a digital information security such as an important document, data, a program of a company or an institution. CONSTITUTION: A company information server(10) is connected to an operator computer(12) and includes various detailed contents of a digital information security operation. A server manager manages the company information server(10) and controls an operation through the operator computer(12). A user in a remote place being connected to a PSDN(Public Switched Data Network)(20) connects to the company information server(10). The user computer(22) receives code company information from the company information server(10). An application tool for a digital information security is installed in a terminal(14) or the user computer(22). A managing tool and various kinds of databases are mounted in the company information server(10) for managing a user who uses the terminal(14) or the user computer(22), and securing/managing supplied(or received) company information.