07336787 is referenced by 73 patents and cites 392 patents.

An encryption arrangement for multiple encryption of television programs. A system according to embodiments of the present invention multiple encrypts only a portion of the data required for full presentation of a television program to permit coexistence of multiple conditional access encryption systems associated with multiple manufacturer's set-top boxes within a single system. In one embodiment, only critical packets such as those carrying a payload incorporating packetized elementary stream header information is encrypted. By only encrypting a portion of the program, dramatically less bandwidth is consumed than the alternative of multiple encryption of all program data, thus permitting a larger number of programs to be carried over the same bandwidth while permitting coexistence of multiple conditional access systems in a single cable television system.

Title
Critical packet partial encryption
Application Number
10/38217
Publication Number
7336787 (B2)
Application Date
January 2, 2002
Publication Date
February 26, 2008
Inventor
Brant L Candelore
Escondido
CA, US
Robert Allan Unger
El Cajon
CA, US
Agent
Jerry A Miller
Miller Patent Services
Assignee
Sony Electronics
NJ, US
Sony Corporation
JP
IPC
H04K 1/00
G06F 12/14
H04N 7/173
H04N 7/16
H04N 7/167
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