Method and system for determining and maintaining trust in digital image files with certifiable time

• US 6,948,069 B1
• Filed: 07/03/2000
• Issued: 09/20/2005
• Est. Priority Date: 07/02/1999
• Status: Expired due to Term

• Current Assignee: Timecertain LLC
• Original Assignee: Timecertain LLC
• Inventors: Teppler, Steven W.
• Primary Examiner(s): Caldwell, Andrew
• Assistant Examiner(s): FIELDS, COURTNEY D
• Application Number:
  US09/609,645
• Time in Patent Office: 1,905 Days
• Field of Search: 713/178, 713/176, 713/175, 713/179, 713/180, 713/181, 713/155, 713/156, 713/186, 713/200, 380/30, 380/23
• US Class Current: 713/178
• 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 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 2209/88 Medical equipments
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3297 involving time stamps, e.g. generation of time stamps

Abstract

A system and methods for proving dates of digital-imaging files, which are accessed, created, modified, received, saved, or transmitted by a computer includes a trusted time source in a tamperproof environment, a first subsystem for saving the file at a moment in time, a second subsystem for retrieving from the trusted time source a date and a time corresponding to the moment in time, a third subsystem for appending the date and the time retrieved from the trusted time source to the saved file, a fourth subsystem for signing the saved file with the date and the time retrieved from the trusted time source appended thereto, a fifth subsystem for hashing the signed file to produce a digest, a sixth subsystem for signing the digest with a key to produce a certificate, a seventh subsystem for appending the certificate to the saved file, and an eighth subsystem for saving the file with the certificate appended thereto. The trusted time source is a real time clock, which is not resettable, is independent of any system clock of the computer, and is installed locally relative to the computer.

Claims

1. A system for maintaining trust in content of a digital image file, comprising:

a trusted time source to provide a certifiable time for an unalterable time stamp, wherein said certifiable time confirms at least one of said digital image file'"'"'s access, creation, modification, receipt, or transmission;

means for receiving said request to save said digital image file from a user;

first means for saving said digital image file at a moment in time;

means for retrieving from said trusted time source a date and a time corresponding to said moment in time, wherein said moment in time is substantially current time of said trusted time source corresponding to receipt of said request;

first means for appending said date and said time retrieved from said trusted time source to said digital image file;

first means for signing said digital image file with said date and said time retrieved from said trusted time source appended thereto;

means for hashing said digital image file to produce a digest;

second means for signing said digest with a key to produce a certificate;

second means for appending said certificate to said digital image file;

second means for saving said digital image file with said certificate appended thereto;

means for modifying said digital image file with said certificate appended thereto into a modified digital image file, wherein said modifying includes at least one of converting or enhancing;

third means for appending said digital image file with said certificate appended thereto to said modified digital image file; and

means for verifying trust in the content of said digital image file with said certificate appended thereto.

2. The system of claim 1, further comprising:

second means for receiving a second request to save said modified digital image file from said user;

third means for saving said modified digital image file at a second moment in time;

second means for retrieving from said trusted time source a second date and a second time corresponding to said second moment in time, wherein said second moment in time is substantially a second current time of said trusted time source corresponding to receipt of said second request;

third means for appending said second date and said second time retrieved from said trusted time source to said modified digital image file;

third means for signing said modified digital image file with said second date and said second time retrieved from said trusted time source appended thereto;

second means for hashing said modified digital image file to produce a second digest;

fourth means for signing said second digest with a second key to produce a second certificate;

fourth means for appending said second certificate to said modified digital image file;

fourth means for saving said modified digital image file with said second certificate appended thereto; and

second means for verifying trust in the content of said modified digital image file with said second certificate appended thereto.

3. The system of claim 2, wherein said modified digital image file with said second certificate appended thereto includes said digital image file with said certificate appended thereto.

4. The system of claim 1, wherein said verification means includes a third means for signing said digital image file with said date and said time retrieved from said trusted time source appended thereto with an identifier.

5. The system of claim 4, wherein said identifier corresponds to said user and is elected from the group consisting of a platform identifier, a server node identifier, and a network identifier.

6. The system of claim 4, wherein said identifier is selected from the group consisting of an identifier corresponding to said user, an identifier corresponding to a system used by said user, and an identifier corresponding to an enterprise within which said user uses said computing means.

7. The system of claim 4, wherein said user identifier is selected from the group consisting of a plurality of characters identifying said user, first data representing an iris scan of said user, second data representing a retina scan of said user, third data representing a finger scan of said user, fourth data representing said user'"'"'s hand geometry, fifth data representing said user'"'"'s voice, sixth data representing said user'"'"'s signature, and combinations of said plurality of characters, first, second, third, fourth, fifth, and sixth data.

8. The system of claim 1, wherein said trusted time source includes a tamper-evident means.

9. A method for maintaining trust in content of a digital image file, comprising:

providing, with a trusted time source, a certifiable time for an unalterable time stamp, wherein said certifiable time confirms at least one of said digital image file'"'"'s access, creation, modification, receipt, or transmission;

receiving said request to save said digital image file from a user;

saving said digital image file at a moment in time;

retrieving from said trusted time source a date and a time corresponding to said moment in time, wherein said moment in time is substantially current time of said trusted time source corresponding to receipt of said request;

appending said date and said time retrieved from said trusted time source to said digital image file;

signing said digital image file with said date and said time retrieved from said trusted time source appended thereto;

hashing said digital image file to produce a digest;

signing said digest with a key to produce a certificate;

appending said certificate to said digital image file;

saving said digital image file with said certificate appended thereto; and

verifying trust in the content of said digital image file with said certificate appended thereto.

10. The method of claim 9, further comprising:

receiving a second request to save said modified digital image file from said user;

saving said modified digital image file at a second moment in time;

retrieving from said trusted time source a second date and a second time corresponding to said second moment in time, wherein said second moment in time is substantially a second current time of said trusted time source corresponding to receipt of said second request;

appending said second date and said second time retrieved from said trusted time source to said modified digital image file;

signing said modified digital image file with said second date and said second time retrieved from said trusted time source appended thereto;

hashing said modified digital image file to produce a second digest;

signing said second digest with a second key to produce a second certificate;

appending said second certificate to said modified digital image file;

saving said modified digital image file with said second certificate appended thereto; and

verifying trust in the content of said modified digital image file with said second certificate appended thereto.

11. The method of claim 9, wherein said modified digital image file with said second certificate appended thereto includes said digital image file with said certificate appended thereto.

12. The method of claim 9, wherein said verification includes signing said digital image file with said date and said time retrieved from said trusted time source appended thereto with an identifier.

13. The method of claim 12, wherein said identifier corresponds to said user and is elected from the group consisting of a platform identifier, a server node identifier, and a network identifier.

14. The method of claim 12, wherein said identifier is selected from the group consisting of an identifier corresponding to said user, an identifier corresponding to a system used by said user, and an identifier corresponding to an enterprise within which said user uses the comprising means.

15. The method of claim 12, wherein said user identifier is selected from the group consisting of a plurality of characters identifying said user, first data representing an iris scan of said user, second data representing a retina scan of said user, third data representing a finger scan of said user, fourth data representing said user'"'"'s hand geometry, fifth data representing said user'"'"'s voice, sixth data representing said user'"'"'s signature, and combinations of said plurality of characters, first, second, third, fourth, fifth, and sixth data.

16. The method of claim 9, wherein said trusted time source includes tamper-evident protection.