Conditional access method and devices

Details Conditional access method and devices Conditional access method and devices

2004-11-04

2009-08-18

Chai, Longbit (Department: 2431)

Cryptography

Video cryptography

Video electric signal modification

C713S189000, C713S190000, C713S191000, C713S193000, C713S194000, C726S027000, C726S028000, C726S029000, C726S030000

Reexamination Certificate

active

07577253

ABSTRACT:
A data stream contains content data that can be decrypted using control words. ECM messages that are included in the stream and contain the control words that is required for decrypting nearby content data. EMM messages contain management information for entitling selected stream receiving devices to decrypt content data from the data stream using control words from ECM messages. Further management information is included in at least some of the ECM messages. The secure device detects The further management information when the control words are supplied and tests whether the further management information is targeted at the stream receiving device (12). If so the secure device indefinitely disables subsequent decryption of at least part of the stream in the stream receiving device (12). In one embodiment, the further management information is targeted by means of a specified condition on entitlement information stored in the secure device. The secure device tests whether any of its entitlement information meets this condition and, if so, disables supply of valid control words.

REFERENCES:
patent: 5799081 (1998-08-01), Kim et al.
patent: 6584199 (2003-06-01), Kim et al.
patent: 2005/0033964 (2005-02-01), Albanese et al.
patent: WO-2003/056823 (2003-07-01), None
“Functional model of a conditional access system”,EBU Project Group B/CA, EBU Technical Review, (Dec. 31, 1995), 68-75.

Affiliated with

Also associated with

Rating

Conditional access method and devices does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Conditional access method and devices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conditional access method and devices will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4118536