Method and system for secure access to non-volatile memory

• US 8,949,624 B2
• Filed: 07/01/2011
• Issued: 02/03/2015
• Est. Priority Date: 03/28/2001
• Status: Expired due to Fees

• Current Assignee: Irdeto USA Incorporated (MultiChoice Group Ltd.)
• Original Assignee: Irdeto USA Incorporated (MultiChoice Group Ltd.)
• Inventors: Kocher, Paul C., Jaffe, Joshua M., Jun, Benjamin C., Laren, Carter C., Pearson, Peter K., Lawson, Nathaniel J.
• Primary Examiner(s): Popham, Jeffrey D
• Application Number:
  US13/175,238
• Publication Number:
  US 20110264923A1
• Time in Patent Office: 1,313 Days
• Field of Search: 726/193
• US Class Current: 713/193
• CPC Class Codes: G06F 21/50 Monitoring users, programs or devices to maintain the integrity of platforms, e.g. of processors, firmware or operating systems
• 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 21/6281 at program execution time, where the protection is within the operating system
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• 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 20/00659 involving a control step which is implemented as an executable file stored on the record carrier
• 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 2209/606 Traitor tracing
• 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: H04N 2005/91342 the copy protection signal being an authentication signal
• CPC Class Codes: H04N 21/25816 : involving client authentication restricting access to computer systems by authenticating users using a predetermined code G06F21/33; cryptographic authentication protocols H04L9/32; networks authentication protocols H04L63/08; authentication in wireless network security H04W12/06
• CPC Class Codes: H04N 21/4135 : external recorder interface circuits between an apparatus for recording television signals and a television receiver H04N5/775
• 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 21/4405 : involving video stream decryption
• CPC Class Codes: H04N 21/44236 : Monitoring of piracy processes or activities protecting computer platforms against harmful, malicious or unexpected behaviour or activities using intrusion detection and counter measures G06F21/566; computer virus detection and handling G06F21/56
• 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 7/1675 : Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

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 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, access secure nonvolatile storage, submit data to CODECs for output, 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. An method executed by one or more computing devices for secure access to a nonvolatile memory, comprising:

receiving, by at least one of the one or more computing devices, a request for privileged access to nonvolatile memory from requesting code, wherein the request includes a code length of the requesting code and a requested priority level;

computing, by at least one of the one or more computing devices, a cryptographic hash of the requesting code using a starting address of the requesting code and the code length;

determining, by at least one of the one or more computing devices, whether the requested priority level is valid based at least in part on one or more of a previous priority level associated with a requested portion of the nonvolatile memory and a predetermined range of acceptable priority levels; and

granting, by at least one of the one or more computing devices, privileged access to the nonvolatile memory based on one of;

a determination that the requested priority level is valid and that the request does not specify an existing portion of the nonvolatile memory;

or

a determination that the requested priority level is valid and that the cryptographic hash matches a value of an authentication hash stored in the requested portion of the nonvolatile memory.

2. An automated method according to claim 1, wherein the request does not specify an existing portion of the nonvolatile memory and further comprising:

allocating, by at least one of the one or more computing devices, a portion of the nonvolatile memory for the requesting code; and

storing, by at least one of the one or more computing devices, the crytographic hash as an authentication hash in the portion of the nonvolatile memory.

3. The method of claim 2, wherein the portion of the nonvolatile memory is allocated to the requesting code based at least in part on a previous priority level associated with the portion of the nonvolatile memory.

4. The method of claim 1, wherein determining whether the requested priority level is valid comprises:

determining whether the requested priority level is greater than the previous priority level allocated to the requested portion of nonvolatile memory; and

designating the requested priority level as valid if it is less than or equal to the previous priority level.

5. The method of to claim 1, wherein the request does not specify an existing portion of the nonvolatile memory and wherein determining whether the requested priority level is valid comprises:

determining whether the requested priority level is greater than a maximum acceptable priority level; and

designating the requested priority level as invalid based at least in part on a determination that it is greater than the maximum acceptable priority level.

6. The method of claim 1, further comprising:

setting a priority level of a portion of the nonvolatile memory to the requested priority level based at least in part on a determination that privileged access was granted.

7. The method of claim 1, further comprising:

in response to a write operation onto a portion of the nonvolatile memory, updating, by at least one of the one or more computing devices, a write counter configured to restrict overwriting of data to the portion of the nonvolatile memory portion when the write counter is above a predetermined threshold.

8. The method of claim 7, further comprising:

rejecting, by at least one of the one or more computing devices, the write operation onto the portion of the nonvolatile memory based at least in part on a value of the write counter.

9. The method of claim 1, wherein determining whether the requested priority level is valid comprises:

determining whether the requested priority level is the maximum acceptable priority level; and

determining whether any portions of the nonvolatile memory having the maximum acceptable priority level also have an associated media identification that is the same as a media identification associated with the requesting code based at least in part on a determination that the requested priority level is the maximum acceptable priority level.

10. A system for secure access to a nonvolatile memory, the system comprising:

one or more processors; and

one or more memories operatively coupled to at least one of the one or more processors and having instructions stored thereon that, when executed by at least one of the one or more processors, cause at least one of the one or more processors to;

receive a request for privileged access to nonvolatile memory from requesting code, wherein the request includes a code length of the requesting code and a requested priority level;

compute a cryptographic hash of the requesting code using a starting address of the requesting code and the code length;

determine whether the requested priority level is valid based at least in part on one or more of a previous priority level associated with a requested portion of the nonvolatile memory and a predetermined range of acceptable priority levels; and

grant privileged access to the nonvolatile memory based on one of;

a determination that the requested priority level is valid and that the request does not specify an existing portion of the nonvolatile memory;

or

a determination that the requested priority level is valid and that the cryptographic hash matches a value of an authentication hash stored in the requested portion of the nonvolatile memory.

11. The system of claim 10, wherein the request does not specify an existing portion of the nonvolatile memory and wherein at least one of the one or more memories has further instructions stored thereon that, when executed by at least one of the one or more processors, cause at least one of the one or more processors to:

allocate a portion of the nonvolatile memory for the requesting code; and

store the crytographic hash as an authentication hash in the portion of the nonvolatile memory.

12. The system of claim 11, wherein the portion of the nonvolatile memory is allocated to the requesting code based at least in part on a previous priority level associated with the portion of the nonvolatile memory.

13. The system of claim 10, wherein the instructions that, when executed by at least one of the one or more processors, cause at least one of the one or more processors to determine whether the requested priority level is valid further cause at least one of the one or more processors to:

determine whether the requested priority level is greater than the previous priority level allocated to the requested portion of nonvolatile memory; and

designate the requested priority level as valid if it is less than or equal to the previous priority level.

14. The system of claim 10, wherein the request does not specify an existing portion of the nonvolatile memory and wherein the instructions that, when executed by at least one of the one or more processors, cause at least one of the one or more processors to determine whether the requested priority level is valid further cause at least one of the one or more processors to:

determine whether the requested priority level is greater than a maximum acceptable priority level; and

designate the requested priority level as invalid based at least in part on a determination that it is greater than the maximum acceptable priority level.

15. At least one non-transitory computer-readable medium storing computer-readable instructions that, when executed by one or more computing devices, cause at least one of the one or more computing devices to:

receive a request for privileged access to nonvolatile memory from requesting code, wherein the request includes a code length of the requesting code and a requested priority level;

compute a cryptographic hash of the requesting code using a starting address of the requesting code and the code length;

determine whether the requested priority level is valid based at least in part on one or more of a previous priority level associated with a requested portion of the nonvolatile memory and a predetermined range of acceptable priority levels; and

grant privileged access to the nonvolatile memory based on one of;

a determination that the requested priority level is valid and that the request does not specify an existing portion of the nonvolatile memory;

or

a determination that the requested priority level is valid and that the cryptographic hash matches a value of an authentication hash stored in the requested portion of the nonvolatile memory.

16. The at least one non-transitory computer-readable medium of claim 15, wherein the request does not specify an existing portion of the nonvolatile memory and further storing computer-readable instructions that, when executed by at least one of the one or more computing devices, cause at least one of the one or more computing devices to:

allocate a portion of the nonvolatile memory for the requesting code; and

store the crytographic hash as an authentication hash in the portion of the nonvolatile memory.

17. The at least one non-transitory computer-readable medium of claim 16, wherein the portion of the nonvolatile memory is allocated to the requesting code based at least in part on a previous priority level associated with the portion of the nonvolatile memory.

18. The at least one non-transitory computer-readable medium of claim 15, wherein the instructions that, when executed by at least one of the one or more computing devices, cause at least one of the one or more computing devices to determine whether the requested priority level is valid further cause at least one of the one or more computing devices to:

determine whether the requested priority level is greater than the previous priority level allocated to the requested portion of nonvolatile memory; and

designate the requested priority level as valid if it is less than or equal to the previous priority level.

19. The at least one non-transitory computer-readable medium of claim 15, wherein the request does not specify an existing portion of the nonvolatile memory and wherein the instructions that, when executed by at least one of the one or more computing devices, cause at least one of the one or more computing devices to determine whether the requested priority level is valid further cause at least one of the one or more computing devices to:

determine whether the requested priority level is greater than a maximum acceptable priority level; and

designate the requested priority level as invalid based at least in part on a determination that it is greater than the maximum acceptable priority level.