Patent ID: 7233669
Filing Date: 2007-06-19
Classification: H04L,H04N

Abstract:
1. A method of selectively encrypting digital video content, comprising; receiving a plurality of unencrypted packets containing the digital video content; selecting certain of the packets of a specified type for encryption according to a selection criterion; encrypting the selected packets using a first encryption key to produce first encrypted packets; encrypting the selected packets using a second encryption key to produce second encrypted packets; wherein the selected packets encrypted using the first encryption key and the selected packets encrypted using the second encryption key contain the same digital video content; replacing the unencrypted packets of the specified packet type with the first encrypted packets and the second encrypted packets in the digital video signal to produce a partially dual encrypted video signal comprised of unencrypted packets along with first and second encrypted packets; wherein the first encryption key is valid for a first segment of time and the second encryption key is valid for a subsequent time segment; and transmitting the partially dual encrypted video signal to a receiver.