System and method for protected content rendering

• US 7,640,438 B2
• Filed: 02/15/2005
• Issued: 12/29/2009
• Est. Priority Date: 02/15/2005
• Status: Expired due to Fees

• Current Assignee: Satyam Computer Services Limited (Tech Mahindra Limited)
• Original Assignee: Satyam Computer Services Limited (Tech Mahindra Limited)
• Inventors: Varadarajan, Sridhar, Rao, Korrapati Kalyana
• Primary Examiner(s): Simitoski; Michael J
• Assistant Examiner(s): Rahim; Monjour
• Application Number:
  US11/058,622
• Publication Number:
  US 20060184805A1
• Time in Patent Office: 1,778 Days
• Field of Search: 380/210, 705/59, 713/168, 713/193, 719/331, 726/26, 726/27
• US Class Current: 713/193
• 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 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 2221/2107 File encryption

Abstract

The use of a variety of devices to render multimedia content is on the increase. It is important ensure that the content owners/providers get their share of return on investment in order to achieve the unlimited global distribution of content. However, illegal use of the delivered content could affect such a return on investment. One of the important requirements is to protect a content and allow for rendering of the protected content in an efficient manner on target devices. A system for protected content rendering involves ensuring that the unprotected content is not available for misuse.

Claims

1. A protected content rendering system to render an encrypted content on a device with a device control circuitry and a plurality of display registers using a plurality of limited buffers for reducing the quantum and time of availability of a plain content of said encrypted content, said system comprising:

means for determining a buffer of said plurality of limited buffers in a random manner;

means for generating a random byte pattern based on said buffer, wherein said random byte pattern is a plurality of random numbers without duplicates with each of said plurality of random numbers is a number between zero and a pre-defined number, wherein said pre-defined number is based on the size of said buffer;

means for obtaining an encrypted block based on said encrypted content;

means for decrypting said encrypted block resulting in a decrypt content;

means for filling said buffer based on said decrypt content and said random byte pattern;

means for making said buffer a part of an incremental portion of said plain content;

means for just-in-time decryption of said encrypted content resulting in a just-in-time portion of said plain content;

means for copying said incremental portion to said plurality of display registers;

means for copying said just-in-time portion to said plurality of display registers; and

means for enabling said device control circuitry to render on said device based on said plurality of display registers.

2. The system of claim 1, wherein said means for just-in-time decryption further comprise:

means for copying a block from said encrypted content to an encrypted block of a limited buffer of said plurality of limited buffers based on an arbitrator, wherein said arbitrator randomly selects said limited buffer from said plurality of limited buffers and randomly selects said encrypted block from said limited buffer;

means for obtaining a plurality of encrypt bytes from said plurality of limited buffers based on said arbitrator and a plurality of signals from said device control circuitry;

means for decrypting said plurality encrypt bytes based on byte-level decryption resulting in said just-in-time portion of said plain content; and

means for providing a control signal to said device control circuitry based on said arbitrator.