Systems and methods using cryptography to protect secure computing environments

• US 7,761,916 B2
• Filed: 08/20/2007
• Issued: 07/20/2010
• Est. Priority Date: 08/12/1996
• Status: Expired due to Fees

• Current Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Original Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Inventors: Sibert, W. Olin, Shear, Victor H., Van Wie, David M.
• Primary Examiner(s): Pyzocha; Michael
• Assistant Examiner(s): Callahan; Paul
• Application Number:
  US11/841,600
• Publication Number:
  US 20080031457A1
• Time in Patent Office: 1,065 Days
• Field of Search: 705/54, 713/156, 713/175, 713/190, 726/22, 717/178
• US Class Current: 726/22
• CPC Class Codes: G06F 12/1483 using an access-table, e.g. matrix or list
• 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 21/51 at application loading time, e.g. accepting, rejecting, starting or inhibiting executable software based on integrity or source reliability
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• CPC Class Codes: G06Q 20/02 involving a neutral party, e.g. certification authority, notary or trusted third party [TTP]
• CPC Class Codes: G06Q 20/085 involving remote charge determination or related payment systems
• CPC Class Codes: G06Q 20/12 specially adapted for electronic shopping systems
• CPC Class Codes: G06Q 20/24 Credit schemes, i.e. "pay after"
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/3823 combining multiple encryption tools for a transaction
• CPC Class Codes: G06Q 20/3825 Use of electronic signatures
• CPC Class Codes: G06Q 20/401 Transaction verification
• 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 20/00159 Parental control systems
• CPC Class Codes: G11B 20/00173 wherein the origin of the content is checked, e.g. determining whether the content has originally been retrieved from a legal disc copy or another trusted source
• CPC Class Codes: G11B 20/00188 involving measures which result in a restriction to authorised devices recording or reproducing contents to/from a record carrier
• CPC Class Codes: G11B 20/00195 using a device identifier associated with the player or recorder, e.g. serial numbers of playback apparatuses or MAC addresses
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00543 wherein external data is encrypted, e.g. for secure communication with an external device or for encrypting content on a separate record carrier
• CPC Class Codes: G11B 20/00557 wherein further management data is encrypted, e.g. sector headers, TOC or the lead-in or lead-out areas
• CPC Class Codes: G11B 20/00688 : said measures preventing that a usable copy of recorded data can be made on another medium
• CPC Class Codes: G11B 20/0071 : involving a purchase action
• CPC Class Codes: G11B 20/00768 : wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 2220/216 : Rewritable discs
• CPC Class Codes: G11B 2220/218 : Write-once discs
• CPC Class Codes: G11B 2220/2562 : DVDs [digital versatile discs]; Digital video discs; MMCDs; HDCDs
• CPC Class Codes: G11B 2220/2575 : DVD-RAMs
• CPC Class Codes: G11B 27/031 : Electronic editing of digitised analogue information signals, e.g. audio or video signals
• CPC Class Codes: G11B 27/329 : on a disc [VTOC]
• CPC Class Codes: H04L 12/40104 : Security; Encryption; Content protection cryptographic protocols H04L9/00; protocols for network security H04L63/00
• CPC Class Codes: H04L 12/40117 : Interconnection of audio or video/imaging devices home automation networks H04L12/2803; bitstream network arrangements specially adapted for distribution of digital video signals H04N7/24

Abstract

Secure computation environments are protected from bogus or rogue load modules, executables and other data elements through use of digital signatures, seals and certificates issued by a verifying authority. A verifying authority—which may be a trusted independent third party—tests the load modules or other executables to verify that their corresponding specifications are accurate and complete, and then digitally signs the load module or other executable based on tamper resistance work factor classification. Secure computation environments with different tamper resistance work factors use different verification digital signature authentication techniques (e.g., different signature algorithms and/or signature verification keys)—allowing one tamper resistance work factor environment to protect itself against load modules from another, different tamper resistance work factor environment. Several dissimilar digital signature algorithms may be used to reduce vulnerability from algorithm compromise, and subsets of multiple digital signatures may be used to reduce the scope of any specific compromise.

Claims

1. A method utilizing a system comprising a processor and a memory encoded with program instructions that, when executed by the processor, cause the processor to perform the method, the method comprising:

receiving a load module and an associated specification;

verifying that the load module performs as specified by the specification;

determining that the load module does not include harmful functionality;

conditionally digitally signing the load module based at least in part on results of the verifying and determining steps; and

distributing, to a remote protected processing environment, a digital signature generated by the step of digitally signing the load module, the remote protected processing environment being operable to perform an authentication step on the digital signature using a public key, and to conditionally execute the load module based at least in part on a result of the authentication step,

wherein the remote protected processing environment is resistant to tampering by an owner of an electronic appliance upon which the remote protected processing environment is running and is operable to maintain the public key as a secret from the owner of the electronic appliance.

2. The method of claim 1, further comprising:

securely distributing the public key to the remote protected processing environment.

3. The method of claim 1, in which the load module, when executed by the electronic appliance, is configured to enable the electronic appliance to play a piece of electronic content.

4. The method of claim 1, in which the load module, when executed by the electronic appliance, is configured to cause the electronic appliance to charge a user a fee for viewing a piece of electronic content.

5. The method of claim 1, in which the load module, when executed by the electronic appliance, is configured to cause the electronic appliance to enable the electronic appliance to perform a financial transaction.

6. The method of claim 1, in which the load module, when executed by the electronic appliance, is configured to cause the electronic appliance to prevent a user from making a copy of a piece of electronic content.

7. The method of claim 1, in which the load module, when executed by the electronic appliance, is configured to cause the electronic appliance to record an aspect of usage of a piece of electronic content.

8. A non-transitory computer-readable medium comprising program code, the program code being operable, when executed by a computer system, to cause the computer system to perform steps comprising:

verifying that a load module performs as specified by a specification associated with the load module;

determining that the load module does not include harmful functionality; and

conditionally digitally signing the load module based at least in part on results of the verifying and determining steps

distributing, to a remote protected processing environment, a digital signature generated by the step of digitally singing the load module; and

securely distributing a cryptographic key to the remote protected processing environment, the cryptographic key being configured for use in authenticating the digital signature.

9. The non-transitory computer-readable medium of claim 8, in which the cryptographic key comprises a public key.

10. A system comprising a processor and a non-transitory computer-readable medium encoded with program instructions that, when executed by the processor,

cause the processor to perform a method comprising:

receiving a load module and an associated specification;

verifying that the load module performs as specified by the specification;

determining that the load module does not include harmful functionality; and

conditionally digitally signing the load module based at least in part on a result of the verifying and determining steps;

distributing, to a remote protected processing environment, a digital signature generated by the digital signing step; and

securely distributing a cryptographic key to the remote protected processing environment, the cryptographic key being configured for use in authenticating the digital signature.

11. The system of claim 10, in which the cryptographic key comprises a public key.