At the server side, set the amount of concurrent users of the client application module, the number of concurrent running works of the client service module and other control variables, use DES encryption algorithm and apply different encryption keys to doubly encrypt the file content and the file itself, and later generates the license file; the license control service module binds the user name, serial number, dongle and other hardware information together and later gets the encrypted license file from the server; resolve this license file to start real-time control of the number of concurrent other client service modules and application modules. The procedure how the license control service module obtains the license file from the server is shown in Figure 2.