PARTIAL PRE-ENCRYPTION WITH NETWORK-BASED PACKET SORTING

摘要

Partial pre-encryption with network-based packet sorting. A video-on-demand (VOD) delivery system for delivering encrypted transport streams to incumbent and overlay set-top boxes utilizes a packet picker/duplicator for sorting selected packets from non-selected packets, duplicating the selected packets, and encrypting one of the pair of duplicated selected packets according to an incumbent encryption scheme. A VOD file server stores the transport stream from the packet picker/duplicator. A network sorter sorts the unencrypted selected packet from the non-selected packets and the encrypted selected packet. The network sorter also sorts the encrypted selected packet from the non-selected packets and encrypts the unencrypted selected packets and the non-selected packets according to an overlay encryption scheme and then sends the transport stream to an overlay set-top box. The network sorter is also responsible for combining the non- selected packets and the incumbent encrypted packets and to send the transport stream to an incumbent set-top box.