Method, system and program product for attaching a title key to encrypted content for synchronized transmission to a recipient

• US 9,300,465 B2
• Filed: 02/20/2008
• Issued: 03/29/2016
• Est. Priority Date: 04/18/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Foster, Eric M., Lotspiech, Jeffrey B., Pestoni, Florian, Plouffe, Wilfred E. Jr., Schaffa, Frank A.
• Primary Examiner(s): WILLIAMS, JEFFERY L
• Application Number:
  US12/034,421
• Publication Number:
  US 20080273702A1
• Time in Patent Office: 2,960 Days
• Field of Search: 380/167, 380/281
• US Class Current: 1/1
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00362 the key being obtained from a media key block [MKB]
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management data processing systems or methods, specially adapted for commerce, e.g. marketing, shopping, billing, auctions or e-commerce G06Q30/00
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner

Abstract

A method and system for attaching a title key to encrypted content for synchronized transmission to, or storage by, a recipient is provided. Specifically, under the present invention, an elementary media stream is parceled into content units that each include a content packet and a header. The content packets are encrypted with one or more title keys. Once the content packets have been encrypted, the title keys are themselves encrypted with a key encrypting key. The encrypted title keys are then attached to the corresponding encrypted content packets for synchronized transmission to a recipient.

Claims

1. A method for processing, with a computing device, encrypted content received by the computing device via a synchronized transmission of an elementary content stream, the method comprising:

receiving, with the computing device, the elementary content stream via a synchronized transmission of a plurality of content units each containing a portion of the elementary content stream and each including a respective header and a respective content packet of the elementary content stream;

retrieving, with the computing device, an encrypted title key, a verifier and identifier information from a respective header of each content unit of the elementary content stream;

generating, with the computing device, a title key by decrypting the encrypted title key with a key encrypting key;

verifying, with the computing device, the title key using the verifier; and

decrypting, with the computing device, the content using the title key.

2. The method of claim 1, wherein the verifier is received encrypted and is then decrypted by the computing device using the title key.

3. The method of claim 1, wherein the retrieving the encrypted title key with the computing device includes retrieving a different encrypted title key from each of at least two respective content units of the plurality of content units.

4. The method of claim 1, wherein the retrieving the encrypted title key with the computing device includes retrieving the encrypted title key, verifier and identifier information from the respective header of a first content unit and retrieving, with the computing device, a second encrypted title key, second verifier, and second information from the respective header of a second content unit.

5. The method of claim 1, wherein the verifier comprises a known value encrypted with the title key.

6. A computer program product stored on a non-transitory recordable storage medium which when executed by a computer system, processes synchronously received content in the form of an elementary content stream broken into a plurality of content units each containing a portion of the elementary content stream, the computer program product comprising:

program code for retrieving, with the computer system, an encrypted title key, a verifier and identifier information from a header attached to each of a plurality of content units of the elementary content stream;

program code for generating, with the computer system, a title key by decrypting the encrypted title key with a key encrypting key;

program code for decrypting, with the computer system, the verifier, wherein the verifier comprises a known value encrypted with the title key;

program code for verifying, with the computer system, the title key using the verifier; and

program code for decrypting, with the computer system, the content using the title key.