This invention relates to a device capable of transmitting in a secured manner a set of films of high visual quality to a display screen of the TV screen type and/or for being recorded on the hard disk or on any other recording support of a box/connector connecting the teletrans-mission/telecommunication network to the display screen such as a TV screen or a personal computer monitor while preserving the audiovisual quality, but avoiding fraudulent use such as the possibility of making pirated copies of films or audiovisual programs recorded on the hard disk or on any other recording support of the set-tope boxy/decoder boxy. The invention also concerns a client-server system and the synchronization mechanism between the server supplying the stream permitting the viewing of the secured digital video film and the client who reads and displays the digital video stream.