Digital signature validation

• US 20030005305A1
• Filed: 06/29/2001
• Published: 01/02/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Brickell, Ernie F.
• Granted Patent: US 7,509,498 B2
• Time in Patent Office: Days
• US Class Current: 713/177
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

A second digital credential that includes a first digital credential and a digital signature is received, and the validity of the second digital credential is determined. A determination is made whether the first digital credential is valid based on the validity of the second digital credential.

Claims

1. A method comprising:

receiving a second digital credential that includes a first digital credential and a digital signature;

determining whether the received second digital credential is valid; and

determining whether the first digital credential is valid based on the validity of the second digital credential.

2. The method of claim 1 wherein determining whether the second digital credential is valid is based on determining the validity of the digital signature.

3. A method comprising:

sending a first digital credential to a first entity that can confirm the validity of the first digital credential;

receiving from the first entity a second digital credential that includes the first digital credential; and

forwarding the second digital credential to a second entity to establish the validity of the first digital credential.

4. The method of claim 3 wherein the first digital credential includes an identifier provided by the first entity in response to a signature request.

5. A method comprising:

receiving from a first entity a first digital credential that includes a first signed document;

checking the validity of the first digital credential;

generating a second digital credential that includes the first digital credential; and

sending the second digital credential to the first entity if the first digital credential is valid.

6. The method of claim 5 wherein the second digital credential includes a validity statement certifying that a source that sent the first digital credential is valid.

7. The method of claim 5 wherein the first signed document includes a message to be signed and a name of a second entity that is an intended destination for the first digital credential.

8. The method of claim 5 wherein the first signed document includes an identifier provided in response to a signature request.

9. The method of claim 5 wherein checking the validity of the first digital credential includes checking whether a first private key is valid.

10. The method of claim 5 wherein checking the first digital credential includes checking the status of the first entity that sent the first digital credential and checking the status of a second entity that is an intended destination for the first digital credential.

11. An apparatus comprising:

at least one port for sending and receiving information; and

a processor configured to;

determine whether a second digital credential is valid, in response to receiving through the at least one port a second digital credential that includes the first digital credential and a second digital signature, and

determine whether the first digital credential is valid based on the validity of the second digital credential.

12. The apparatus of claim 11 wherein the processor is configured to determine whether the first digital credential is valid based on determining the validity of the digital signature.

14. The apparatus of claim 13 wherein the first digital credential includes an identifier provided by the first entity in response to a signature request.

16. The apparatus of claim 15 wherein the second digital credential includes a validity statement certifying that a source that sent the first digital credential is valid.

17. The apparatus of claim 15 wherein the first signed document includes a message to be signed and a name of a second entity that is an intended destination for the first digital credential.

18. The apparatus of claim 15 wherein the first signed document includes the identifier provided by the first entity in response to a signature request.

19. The apparatus of claim 15 wherein the processor is configured to check the validity of the first digital credential by checking whether a first private key is valid.

20. The apparatus of claim 15 wherein the processor is configured to check the status of the first entity that sent the first digital credential and check the status of a second entity that is an intended destination for the first digital credential.

13. An apparatus comprising:

at least one port for sending and receiving information;

and

a processor configured to;

send through the at least one port a first digital credential to a first entity that can confirm the validity of the digital credential, and

forward through the at least one port a second digital credential to a second entity, in response to receiving through the at least one port from the first entity the second digital credential that includes the first digital credential.

15. An apparatus comprising:

at least one port for sending and receiving information;

and

a processor configured to;

check the validity of a first digital credential, in response to receiving through the at least one port from a first entity the first digital credential that includes a first signed document, and

generate a second digital credential that includes the first digital credential, and

send through at least one port from the first entity the second digital credential if the first digital credential is valid.

21. An article comprising a computer-readable medium that stores computer executable instructions for causing a computer system to:

determine whether a second digital credential is valid, in response to receiving a second digital credential that includes the first digital credential and a second digital signature; and

determine whether the first digital credential is valid based on the validity of the second digital credential.

22. The article of claim 21 including instructions for causing the computer system to determine whether the first digital credential is valid is based on determining the validity of the second digital signature.

24. The article of claim 23 wherein including instructions to for causing the computer system to send a first digital credential including an identifier provided by the first entity in response to a signature request.

26. The article of claim 25 including instructions for causing the computer system to include in the second digital credential a validity statement that certifies that a source that sent the first digital credential is valid.

27. The article of claim 25 including instructions for causing the computer system to include in the first signed document a message to be signed and a name of a second entity that is an intended destination for the first digital credential.

28. The article of claim 25 wherein the instructions include instructions to include in the first signed document an identifier provided in response to a signature request.

29. The article of claim 25 including instructions for causing the computer system to check the validity of the first digital credential by checking whether a first private key is valid.

30. The article of claim 25 wherein the instructions to check the first digital credential includes instructions to check the status of the first entity that sent the first digital credential and check the status of a second entity that is the intended destination for the first digital credential.

23. An article comprising a computer-readable medium that stores computer executable instructions for causing a computer system to:

send a first digital credential to a first entity that can confirm the validity of the digital credential; and

forward a second digital credential to a second entity, in response to receiving from the first entity the second digital credential that includes the first digital credential.

25. An article comprising a computer-readable medium that stores computer executable instructions for causing a computer system to:

check the validity of a first digital credential, in response to receiving from a first entity the first digital credential that includes a first signed document;

generate a second digital credential that includes the first digital credential; and

send the second digital credential to the first entity if the first digital credential is valid.