System and method for protected content rendering

• US 20060184805A1
• Filed: 02/15/2005
• Published: 08/17/2006
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Satyam Computer Services Limited (Tech Mahindra Limited)
• Original Assignee: Satyam Computer Services Limited (Tech Mahindra Limited)
• Inventors: Varadarajan, Sridhar, Rao, Korrapati Kalyana
• Granted Patent: US 7,640,438 B2
• Time in Patent Office: Days
• 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 for reducing the quantum and time of availability of plain content, said system comprising:

(a) a page selection subsystem for processing a protected content file;

(b) an incremental decryption subsystem for block level decryption;

(c) a scrambler subsystem for randomizing plain content;

(d) a random pattern generator subsystem for generating a random number and random byte pattern;

(e) a rendering engine subsystem for rendering randomized plain content;

(f) a plurality of buffers with limited capacity; and

(g) a database for storing and providing protected content.

2. The system of claim 1, wherein said page selection subsystem comprises means for processing a protected content file comprising:

obtaining of a plurality of decrypt keys associated with said protected content file, sending of said plurality of keys to said incremental decryption subsystem, sending of a protected page of said protected content file to said incremental decryption subsystem, receiving of a signal from said rendering engine subsystem, and sending of completion message to said incremental decryption subsystem.

3. The system of claim 1, wherein said incremental decryption subsystem comprises means for processing block level protected content comprising:

obtaining of a plurality of decrypt keys from said page selection subsystem, obtaining of a predetermined block size, obtaining of a page from said page selection subsystem, dividing of said page into a plurality of blocks based on said predetermined block size, ordering of said plurality of blocks into a plurality of ordered blocks, selection of an ordered block from said plurality of ordered blocks, decryption of said order block using said plurality of decrypt keys, sending of a message to said scrambler subsystem, and receiving of a signal from said rendering engine subsystem.

4. The system of claim 1, wherein said scrambler subsystem comprises means for processing block level plain content comprising:

obtaining of a plain block, obtaining of a random pattern from said random pattern generator subsystem, determination of a buffer id from said random pattern, determination of a byte pattern from said random pattern, filling of a buffer associated with said buffer id using said plain block and said byte pattern, and sending of a message to said rendering engine subsystem.

5. The system of claim 1, wherein said random pattern generator subsystem comprises means for generating a random pattern based on a seed value comprising:

initialization of said seed value, updating of said seed value, receiving of a signal from said rendering engine subsystem, generation of a random buffer id, generation of a random byte pattern, packaging of said random buffer id and random byte pattern into said random pattern, and sending of said random pattern to said scrambler subsystem and said rendering engine subsystem.

6. The system of claim 1, wherein said rendering engine subsystem comprises means for processing a block of plain content comprising:

receiving of internal clock, sending of next page signal to said page selection subsystem, sending of next block signal to said random pattern generator subsystem and incremental decryption subsystem, receiving of a random pattern from said random pattern generator subsystem, determination of a buffer id from said random pattern, determination of a byte pattern from said random pattern, extraction of plain content from a buffer associated with said buffer id using said byte pattern into said block of plain content, and populating of a plurality of device registers associated with device Circuits using said block of plain content.

7. An apparatus, for protected content rendering on a target device, coupled to a computation system, comprising:

(a) a processor for providing compute support and control support;

(b) a main memory for supporting PS, SS, and RPG subsystems;

(c) a protected content buffer to hold protected content;

(d) an arbitrator for random distribution of content from said protected content buffer to one of a plurality of limited buffers;

(e) an ID subsystem realized in hardware;

(f) an RE subsystem realized in hardware comprising;

a plurality of device registers of said target device; and

a control circuitry of said target device;

and

(g) a control circuitry interconnecting said control circuitry of said target device, said processor, said arbitrator, and said ID subsystem.