U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Conditional access system

Patent 6510519 Issued on January 21, 2003. Estimated Expiration Date: Icon_subject June 14, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

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More ...

Inventors

Assignee

Application

No. 881428 filed on 06/14/2001

US Classes:

713/168, Particular communication authentication technique380/239, Encrypted code control signal380/259, Symmetric key cryptography380/277, KEY MANAGEMENT713/169, Mutual entity authentication713/170Authentication of an entity and a message

Examiners

Primary: Barron, Gilberto Jr.
Assistant: Zand, Kambiz

Attorney, Agent or Firm

Foreign Patent References

  • 0 723 371 EP. 07/13/1996
  • 0 752 786 EP. 01/13/1997
  • WO 94/13107 WO. 06/13/1994
  • WO 95/29560 WO. 11/13/1995

International Classes

H04L 009/00
H04N 007/167

Abstract

A cable television system provides conditional access to services. The cable television system includes a headend from which service "instances", or programs, are broadcast and a plurality of step top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.

Other References

  • ISO/IEC 13818-1, "Information Technology--Generic Coding of Moving Pictures and Associated Audio Systems," Draft of: Nov. 13, 1994
  • ISO/IEC JTC1/SC29/WG11, "Universal Multi-Program Multiplex and Transport for MPEG-2 Systems," Jan. 1993
  • ISO/IEC JTC1/SC29/WG11, "An MGEG-2 Multi-Program Multiplex Syntax," Jan. 1993
  • ISO/IEC JTC1/WG11, "Requirements and Method for High-Level Multiplexing of MPEG and Other Digital Service Bitstreams with Universal Transport Layer," Nov. 1992
  • Whitfield, Diffie, "Authentication and Authenticated Key Exchanges," Designs, Codes and Cryptography, An International Journal, vol. 2, No. 2, Jun. 1992, pp. 107-125
  • Schneier, Bruce, "Applied Cryptography Second Edition: Protocols, Algorithms and Source Code in C," pp. 357-363
  • Menezes, Alfred J., "Handbook of Applied Cryptography," pp. 506-525
  • TM-1244 Rev. 4, "Final Technical Report of the Conditional Access Specialist Group," Nov. 17, 1994
  • Coutrot et al., "A Single Conditional Access System for Satellite-Cable and Terrestrial TV," IEEE Transactions on Consumer Electronics, vol. 35, No. 3, Aug. 1989, pp. 464-468
  • Louis Claude Guillou and Jean-Luc Giachetti, "Encipherment and Conditional Access," SMPTE Journal, 103 (1994) Jun., No. 6, White Plains, N
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