System and methods for generating trusted and authenticatable time stamps for electronic documents

• US 6,393,126 B1
• Filed: 02/22/2000
• Issued: 05/21/2002
• Est. Priority Date: 06/23/1999
• Status: Expired due to Term

• Current Assignee: Ip Gem Group, LLC
• Original Assignee: Datum Incorporated (Microchip Technology Incorporated)
• Inventors: Robinson, David, van der Kaay, Erik H., Dowd, Gregory L., Tyo, David
• Primary Examiner(s): Decady, Albert
• Assistant Examiner(s): JACK, TODD M
• Application Number:
  US09/510,408
• Time in Patent Office: 819 Days
• Field of Search: 380/239, 380/241, 380/36, 713/159, 713/172, 713/178, 713/185
• US Class Current: 380/241
• CPC Class Codes: G06F 21/725 operating on a secure reference time value
• CPC Class Codes: G06F 2221/2115 Third party
• CPC Class Codes: G06F 2221/2151 Time stamp
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions
• CPC Class Codes: H04L 2463/102 applying security measure for e-commerce data processing systems or methods, specially adapted for e-commerce G06Q30/00
• CPC Class Codes: H04L 2463/121 Timestamp cryptographic mechanisms or cryptographic arrangements involving time stamps H04L9/3297
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 63/126 the source of the received data

Abstract

A trusted time infrastructure system provides time stamps for electronic documents from a local source. The system comprises a trusted master clock, a trusted local clock, and a network operations center. The trusted master clock and network operations center are located within secure environments controlled by a trusted third party. The trusted local clock may be located in an insecure environment. The trusted master clock is certified to be synchronized with an accepted time standard, such as a national time server. The trusted local clock, which issues time stamps, is certified to be synchronized with the trusted master clock. Time stamps and certifications are signed by the issuing device using public key cryptography to enable subsequent authentication. The network operations center logs clock certifications and responds to requests for authentication of time stamps.

Claims

1. A system for providing a source of time certified to be synchronized with an accepted standard, the system comprising:

a trusted master clock certified through a first certificate to be synchronized to the accepted standard, the trusted master clock maintained within a secure environment under control of a trusted third party;

a trusted local clock certified by the trusted master clock through a second certificate to be synchronized with the trusted master clock, the trusted local clock being a tamper-resistant device configured to be located in an insecure environment; and

a network operations center configured to provide verification information for verifying the certification of the synchronization of clocks within the system, the network operations center maintained within a secure environment under control of a trusted third party.

2. The system of claim 1, wherein the first and second certificates are cryptographically signed and wherein the first certificate and the second certificate can be the same certificate.

3. The system of claim 1, wherein the verification information comprises a public key of a clock.

4. The system of claim 1, wherein the trusted local clock is configured to provide trusted temporal tokens that cryptographically bind data to time.

5. The system of claim 4, wherein the verification information comprises an indication of the validity of a submitted trusted temporal token.

6. The system of claim 1, wherein the network operations center is further configured to receive certification information from the trusted master clock.

7. The system of claim 6, wherein the certification information comprises a time calibration certificate of a certified clock.

8. The system of claim 1, wherein the network operations center is further configured to log time calibration certificates.

9. A system for time stamping digital documents, wherein the time foot which the time stamp is derived is certified to be synchronized to an accepted standard the system comprising:

a trusted master clock certified to be synchronized to the accepted standard through a first cryptographically signed certificate, the trusted master clock maintained within a secure environment under control of a trusted third party;

a trusted local clock certified by the trusted master clock to be synchronized with the trusted master clock through a second cryptographically signed certificate, the trusted local clock configured to provide time stamps, the trusted local clock being a tamperresistant device configured to be located in an insecure environment; and

a network operations center configured to provide time stamp verification information, the network operations center maintained within a secure environment under control of a trusted third party.

10. The system of claim 9, wherein the verification information comprises a time calibration certificate of a certified clock.

11. The system of claim 9, wherein the verification information comprises a public key of a clock.

12. The system of claim 9, wherein the verification information comprises an indication of the validity of a submitted time stamp.

13. The system of claim 9, wherein the network operations center is further configured to log time calibration certificates.

14. A method of providing trusted temporal tokens, the method comprising:

maintaining a red master clock within a secure environment;

causing the trusted master clock to be certified through a first certificate as synchronized with a trusted time server;

certifying a trusted local clock through a second certificate to be synchronized with the trusted master clock, the trusted local clock being configured to provide trusted temporal tokens, the trusted local clock being a tamper-resistant device configured to be located in an insecure environment; and

providing busted temporal token verification information in response to verification requests.

15. The method of claim 14, further comprising providing trusted temporal tokens through the trusted local clock in response to time stamping requests.

16. The method of claim 14, wherein the first and second certificates are cryptographically signed and wherein the first certificate and the second certificate can be the same certificate.

17. The method of claim 14, wherein the verification information comprises a public key of a clock.

18. The method of claim 14, wherein the verification information comprises an indication of the validity of a trusted temporal token.

19. The method of claim 14, wherein the verification information is provided by a network operations center, the network operations center being maintained within a secure environment.

20. The method of claim 14, further comprising logging the certifications of the clocks.

21. The method of claim 14, fiber comprising logging the number of trusted temporal tokens issued by the trusted local clock.

23. The method of claim 14, further comprising billing a client in exchange for certifying the synchronization of the trusted local clock.

22. The method of clam 14, further comprising billing a client based on the number of temporal tokens issued to the client.

24. A system for providing time certified to be synchronized with a trusted source, the system comprising:

a trusted clock configured to provide time, the trusted clock certified through a chain of at least two signed certificates to be synchronized to the trusted source, wherein each of the signed certificates certifies that two clocks are synchronized; and

a verification module configured to provide verification information for verifying the synchronization of thee trusted clock with the trusted source, wherein the verification module provides the verification information based at least upon the chain of signed certificates.

25. The system of claim 24, wherein the signed certificates are digitally signed.

26. The system of claim 24, wherein the signed certificates are cryptographically signed.

27. The system of claim 24, wherein the verification information comprises at least one of the signed certificates.

28. The system of claim 24, wherein the verification information comprises the signed certificates.

29. The system of claim 24, wherein the verification information comprises an indication that the trusted clock has been certified to be synchronized to the trusted source.