Long-life digital certification for publishing long-life digital content or the like in content rights management system or the like

• US 20060206712A1
• Filed: 03/10/2005
• Published: 09/14/2006
• Est. Priority Date: 03/10/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Paramasivam, Muthukrishnan, LaMacchia, Brian, Dillaway, Blair Brewster, Manferdelli, John
• Granted Patent: US 7,549,051 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2209/68 Special signature format, e.g. XML format
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3265 using certificate chains, trees or paths; Hierarchical trust model

Abstract

A digital certificate is employed to produce a digital signature for a digital construct. In the digital certificate is set forth a certificate validity period defining for the digital certificate a time period during which the digital certificate is to be honored as valid for producing digital signatures, and a signature validity period defining for each digital signature produced based on the digital certificate a time period during which the digital signature is to be honored as valid.

Claims

1. A computer-readable medium having stored thereon a digital structure defining a digital certificate for being employed to produce a digital signature for a digital construct, the digital certificate having a public-private key pair associated therewith, the private key for being employed to produce the digital signature, the public key for being employed to validate the digital signature, the data structure comprising:

a first field setting forth the public key associated with the digital certificate;

a second field setting forth a signature creation validity period defining for the digital certificate itself and the private key thereof a time period during which the digital certificate itself and the private key thereof are to be honored as valid for producing digital signatures; and

a third field separate from the second field and setting forth a signature validity period defining for each digital signature produced based on the digital certificate a time period during which the digital signature is to be honored as valid.

2. The medium of claim 1 wherein the signature creation validity period is a relatively shorter time period and the certificate validity period is a relatively longer time period.

3. The medium of claim 1 wherein the data structure further comprises a fourth field setting forth at least one type of digital construct that may be signed based on the digital certificate.

4. The medium of claim 1 wherein the digital structure defines the digital certificate according to an extensible Markup Language (XML) that defines a standard with both the certificate validity period and the signature creation validity period.

5. The medium of claim 4 wherein the XML-defined standard is the MPEG Rights Expression Language (REL) as approved by the International Organization for Standardization (ISO).

6. The medium of claim 1 wherein each of the signature creation validity period and the certificate validity period is set forth within the digital structure as a policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including a time period.

7. The medium of claim 1 wherein the digital structure includes a plurality of policies, each with regard to one of a signature creation validity period and a certificate validity period, each policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including a time period.

8. The medium of claim 1 wherein the digital structure comprises a plurality of the signature creation validity periods, each signature creation validity period being set forth within the digital structure as a policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including the time period corresponding to the signature creation validity period.

9. The medium of claim 1 wherein the digital structure comprises a plurality of the certificate validity periods, each certificate validity period being set forth within the digital structure as a policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including the time period corresponding to the certificate validity period.

10. The medium of claim 1 wherein the digital structure includes a plurality of policies, each with regard to a right or condition that is to be honored in connection with use of the digital construct, each policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right.

11. A computer-readable medium having stored thereon a digital structure defining a digital construct with a digital signature and an attached chain including a digital certificate having been employed to produce the digital signature for the digital construct, the digital certificate having a public-private key pair associated therewith, the private key having been employed to produce the digital signature, the public key for being employed to validate the digital signature, the data structure comprising:

a first field setting forth the public key associated with the digital certificate;

a second field setting forth a signature creation validity period defining for the digital certificate itself and the private key thereof a time period during which the digital certificate itself and the private key thereof are to be honored as valid for producing the digital signature of the digital construct; and

a third field separate from the second field and setting forth a certificate validity period defining for the digital signature of the digital construct as produced based on the digital certificate a time period during which the digital signature of the digital construct is to be honored as valid.

12. The medium of claim 11 wherein the signature creation validity period is a relatively shorter time period and the certificate validity period is a relatively longer time period.

13. The medium of claim 11 wherein the data structure further comprises a fourth field setting forth at least one type of digital construct that may be signed based on the digital certificate.

14. The medium of claim 11 wherein the digital structure defines the digital certificate according to an extensible Markup Language (XML) that defines a standard with both the signature creation validity period and the certificate validity period.

15. The medium of claim 14 wherein the XML-defined standard is the MPEG Rights Expression Language (REL) as approved by the International Organization for Standardization (ISO).

16. The medium of claim 11 wherein each of the signature creation validity period and the certificate validity period is set forth within the digital certificate as a policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including a time period.

17. The medium of claim 11 wherein the digital certificate includes a plurality of policies, each with regard to one of a signature creation validity period and a certificate validity period, each policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including a time period.

18. The medium of claim 11 wherein the digital certificate comprises a plurality of the certificate validity periods, each signature creation validity period being set forth within the digital certificate as a policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including the time period corresponding to the certificate validity period.

19. The medium of claim 11 wherein the digital certificate comprises a plurality of the certificate validity periods, each certificate signature validity period being set forth within the digital certificate as a policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right, the constraints including the time period corresponding to the signature validity period.

20. The medium of claim 11 wherein the digital certificate includes a plurality of policies, each with regard to a right or condition that is to be honored in connection with use of the digital construct, each policy including a particular principal, a right granted to the principal, a type of digital construct with which the right can be exercised, and constraints on the right.