Patent ID: 7310423

Claim:
A method for decrypting a plurality of encrypted transport streams, each transport stream comprising at least two elementary streams each containing a plurality of packets, with a single-stream decryption engine, comprising: tagging packets of the elementary streams in each of the plurality of encrypted transport streams which are encrypted with a tag value to indicate their origin transport stream; merging only the tagged packets from the plurality encrypted transport streams which are encrypted into a merged transport stream to be provided to a decryption unit; decrypting packets in the merged transport stream with the decryption engine to produce a decrypted merged transport stream; and splitting the decrypted merged transport stream into a plurality of decrypted transport streams equal in number to the plurality of encrypted transport streams by routing packets in the decrypted merged transport stream to specific decrypted transport streams according to their tag value, wherein the step of merging only the tagged packets from the plurality encrypted transport streams which are encrypted is performed based on a packet identifier (PID) value within a packet tag, and whereby packets of elementary streams which are not encrypted are passed to an output stream without being processed by the decryption engine.