METHOD AND APPARATUS FOR SECURE SHARING OF RECORDED COPIES OF A MULTICAST AUDIOVISUAL PROGRAM USING SCRAMBLING AND WATERMARKING TECHNIQUES

摘要

A method for secure distribution of an original audiovisual stream to a plurality of consumer devices through a multicast session includes generating a protected audiovisual stream by modifying the original audiovisual stream; a complementary stream of any format including digital information suitable to allow reconstruction of an audiovisual stream from the protected stream; calculating a first mark as function of a unique identifier of a receiving consumer device or an external secure device; calculating on the receiving consumer device a first marked audiovisual stream from the protected stream as function of the first mark and the complementary stream; transmitting the protected stream from the receiving device to the second device; calculating a second mark as function of a unique identifier of a second device, an external secure device or a consumer using the second device; and calculating on the second consumer device a second marked audiovisual stream from the protected stream received from the receiving device as function of the second mark.