Content protection for transmission systems

• US 5,949,877 A
• Filed: 01/30/1997
• Issued: 09/07/1999
• Est. Priority Date: 01/30/1997
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Traw, Chandler Brendan Stanton, Aucsmith, David Wayne
• Primary Examiner(s): Stamber, Eric W.
• Assistant Examiner(s): Darrow, Justin T.
• Application Number:
  US08/791,245
• Time in Patent Office: 950 Days
• Field of Search: 380/30, 380/4, 380/21
• US Class Current: 713/171
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/445 by mutual authentication, e.g. between devices or programs
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00123 the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: H04L 12/40104 Security; Encryption; Content protection cryptographic protocols H04L9/00; protocols for network security H04L63/00
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/0841 involving Diffie-Hellman or related key agreement protocols
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]

Abstract

A method for protecting digital content from copying and/or other misuse as it is transferred between devices over insecure links, includes authenticating that both a content source and a content sink are compliant devices, establishing a secure control channel between the content source and the content sink, establishing a secure content channel, providing content keys, and transferring content.

In a further aspect of the present invention, at least one certificate revocation list version identifier is exchanged between the content source and the content sink, and if the received certificate revocation list version identifier is more recent than the certificate revocation list version identifier stored in the receiving device, then the certificate revocation list of the receiving device is updated.

Claims

1. A method of distributing protected content, the method comprising the steps of:

a) authenticating a content sink by a content source;

b) authenticating a content source by a content sink;

c) establishing a secure control channel;

d) comparing the relative creation dates of at least two certificate revocation lists;

e) establishing a secure content channel; and

f) transferring content from content source to content sink.

2. The method of claim 1, wherein the step of establishing a secure control channel comprises the step of performing a Diffie-Hellman key exchange.