Patent ID: 7484103

Claim:
A multimedia contents protecting system for preventing multimedia contents, which are sent to an application program running on a client system, from leaking without permission through the use of an information providing system and the client system, the information providing system and the client system each having a Central Processing Unit (CPU), a volatile storage (memory), a non-volatile storage (hard disk) and an input/output device (keyboard, monitor, etc.), and being connected to each other through wired or wireless internal communication means or means for communicating with an external network, comprising: the information providing system comprising, encryption means ( 110 ) for encrypting original contents using one or more encryption keys and generating an encrypted contents package ( 121 ), provision means ( 120 ) for holding the encrypted contents package ( 121 ) and providing the encrypted contents package ( 121 ) to users on line, and a Digital Rights Management (DRM) server ( 130 ) for managing generation of the encryption keys and performing various authentication operations; and the client system comprising, filtering means located between an application program ( 144 ) on a higher layer and a device driver on a lower layer for repeating a process of hooking data packet of the encrypted contents package ( 121 ) with messages between the application program and the device driver, converting the data packet to a format corresponding to decryption, decrypting the encrypted data packet using one or more decryption keys, and sending the decrypted data packet to the application program, control means for starting and terminating the application program and controlling the filtering means, and an application program ( 144 ) for receiving the contents from the filtering means and playing the contents.