Reprogrammable security for controlling piracy and enabling interactive content

• US 20070033419A1
• Filed: 07/07/2004
• Published: 02/08/2007
• Est. Priority Date: 07/07/2003
• Status: Active Grant

• Current Assignee: Irdeto USA Incorporated (MultiChoice Group Ltd.)
• Original Assignee: Cryptography Research, Inc. (Rambus Inc.)
• Inventors: Jun, Benjamin, Lawson, Nathaniel, Kocher, Paul, Jaffe, Joshua, Pearson, Peter, Laren, Carter
• Granted Patent: US 8,055,910 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 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57
• CPC Class Codes: G06Q 50/188 Electronic negotiation
• 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 20/00115 wherein the record carrier stores a unique medium identifier
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00231 wherein the key is obtained from a local external medium, e.g. a card
• CPC Class Codes: G11B 20/00246 wherein the key is obtained from a local device, e.g. device key initially stored by the player or by the recorder
• CPC Class Codes: G11B 20/00253 wherein the key is stored on the record carrier
• CPC Class Codes: G11B 20/00449 content scrambling system [CSS]
• CPC Class Codes: G11B 20/00818 wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• CPC Class Codes: H04L 9/302 involving the integer factorization problem, e.g. RSA or quadratic sieve [QS] schemes
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3249 using RSA or related signature schemes, e.g. Rabin scheme
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04N 2005/91342 : the copy protection signal being an authentication signal
• CPC Class Codes: H04N 2005/91364 : the video signal being scrambled
• CPC Class Codes: H04N 21/4181 : for conditional access
• CPC Class Codes: H04N 21/42646 : for reading from or writing on a non-volatile solid state storage medium, e.g. DVD, CD-ROM
• CPC Class Codes: H04N 21/4325 : by playing back content from the storage medium reproduction of recorded television signals H04N5/76; reproduction of recorded television signals H04N9/79
• CPC Class Codes: H04N 21/4405 : involving video stream decryption
• CPC Class Codes: H04N 21/4627 : Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/8193 : dedicated tools, e.g. video decoder software or IPMP tool
• CPC Class Codes: H04N 21/8358 : involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 5/913 : for scrambling ; for copy protection

Abstract

Technologies are disclosed to transfer responsibility and control over security from player makers to content authors by enabling integration of security logic and content. An exemplary optical disc (200) carries an encrypted digital video title combined with data processing operations that implement the title'"'"'s security policies and decryption processes. Player devices include a processing environment (e.g., a real-time virtual machine), which plays content by interpreting its processing operations. Players also provide procedure calls to enable content code to load data from media, perform network communications, determine playback environment configurations (225), access secure non-volatile storage, submit data to CODECs for output (250), and/or perform cryptographic operations. Content can insert forensic watermarks in decoded output for tracing pirate copies. If pirates compromise a player or title, future content can be mastered with security features that, for example, block the attack, revoke pirated media, or use native code to correct player vulnerabilities.

Claims

1. A method for regulating access to nonvolatile digital storage contained in a device executing instructions in a Touring-complete interpreter, said method comprising:

(a) receiving a request from said instructions being executed, wherein said request specifies;

(i) a portion of said storage for which access is requested, and

(ii) a plurality of additional executable instructions;

(b) applying a cryptographic hash function to said additional executable instructions to obtain a hash value;

(c) authenticating said hash value; and

(d) provided that said authentication is successful, enabling access to said requested portion of said storage while executing said additional executable instructions.

2. The method of claim 1 wherein said step of authenticating comprises comparing said hash value with a hash value stored in said nonvolatile storage.

3. The method of claim 1 wherein said step of authenticating comprises verifying a digital signature provided by said instructions being executed.

4. The method of claim 1 wherein said request includes a pointer to said additional executable instructions in memory accessible by said instructions being executed and contained in said device.

5. A digital optical disc medium containing encrypted audiovisual content for playback on any of a plurality of device architectures, said digital optical disc medium comprising program logic configured to:

(a) identify at least one characteristic of a device executing said program logic;

(b) use said at least one characteristic to determine which, if any, of a plurality of security weaknesses are present in said executing device;

(c) when said determination indicates a suspected weakness,

(i) select at least one of a plurality of software countermeasures, wherein said selected countermeasure corresponds to said suspected weakness and is compatible with said executing device;

(ii) mitigate said suspected weakness by directing said executing device to invoke said selected countermeasure; and

(iii) decode said encrypted audiovisual content, wherein said decoding includes a result produced by successful operation of said countermeasure logic; and

(d) when said determination does not indicate a suspected weakness, decode said audiovisual content using at least one decryption key derived using at least one cryptographic key associated with said executing device.

6. The digital optical disc medium of claim 5 wherein said program logic is configured to execute in an interpreter common to said plurality of device architectures, and at least a portion of said selected countermeasure is configured to be executed directly as native code on a microprocessor associated with said executing device.

7. The digital optical disc medium of claim 5 wherein said digital optical disc medium further includes a digital signature authenticating said native code portion.

8. An automated method for enabling a playback device containing a nonvolatile memory to determine whether permission to use digital optical disc media has been revoked, said method comprising:

(a) reading a media identifier from a digital optical disc medium;

(b) verifying that said media identifier is not represented in a revocation list stored in nonvolatile memory;

(c) storing said media identifier in a playback history contained in said nonvolatile memory;

(d) reading a list of revoked media identifiers from said digital optical disc media;

(e) noting any media identifier that is represented in said playback history and is also represented on said read list of revoked media identifiers; and

(f) adding any said noted media identifier to said revocation list contained in said nonvolatile memory.

9. The method of claim 8 wherein playback of encrypted audiovisual content contained on said digital optical disc medium is prevented when said verifying step determines that the media identifier is represented in said revocation list.

10. The method of claim 8 wherein playback of encrypted audiovisual content contained on said digital optical disc medium is performed at reduced quality when said verifying step determines that the media identifier is represented in said revocation list.

11. An automated method for determining whether to allow a portion of software stored in a computer-readable memory to access a portion of a nonvolatile memory, the method comprising:

(a) receiving a reference to said portion of software;

(b) computing a cryptographic hash of said software portion;

(c) comparing said computed cryptographic hash with a value stored in said nonvolatile memory;

(d) when said computed cryptographic hash matches said stored value, allowing said software portion to access said nonvolatile memory portion; and

(e) when said computed cryptographic hash does not match said stored value, not allowing said software portion to access said nonvolatile memory.