Method and apparatus for secure document timestamping

• US 6,263,438 B1
• Filed: 09/08/1998
• Issued: 07/17/2001
• Est. Priority Date: 03/21/1996
• Status: Expired due to Term

• Current Assignee: Inventor Holdings LLC (Walker Innovation Inc. (f/k/a Patent Properties, Inc.))
• Original Assignee: Walker Digital LLC (Walker Innovation Inc. (f/k/a Patent Properties, Inc.))
• Inventors: Jorasch, James A., Schneier, Bruce, Walker, Jay S.
• Primary Examiner(s): Peeso, Thomas R.
• Application Number:
  US09/149,024
• Time in Patent Office: 1,043 Days
• Field of Search: 713/178, 713/182, 713/194, 713/200, 713/201, 380/243, 380/255
• US Class Current: 713/178
• CPC Class Codes: G07D 7/0047 using checkcodes, e.g. coded numbers derived from serial number and denomination
• CPC Class Codes: H04L 2209/805 Lightweight hardware, e.g. radio-frequency identification [RFID] or sensor
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04L 9/3297 involving time stamps, e.g. generation of time stamps
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

The invention relates devices and methods for creating a cryptographically assured timestamp that can be verified by a party that was not present during the creation of the timestamp. The timestamp is applied to physical documents, and other substrates capable of receiving an optically detectable mark, that are to be transmitted to temporally or spatially distant recipients.

Claims

1. An apparatus for secure document timestamping, comprising:

a time generator for generating a representation of the time;

a computing device, including a computer processor and a memory, coupled to receive the representation of the time from the time generator and programmed to perform a cryptographic operation on the representation of the time to produce a timestamp;

an output device, coupled to the computing device, for outputting the timestamp in optically detectable form to a physical document in response to automatic detection by the apparatus of a triggering event; and

means for rendering at least one of the time generator and the computing device resistant to tampering.

2. The apparatus of claim 1, wherein the computing device is programmed to automatically detect the triggering event based on a schedule stored in the memory.

3. The apparatus of claim 2, wherein the computing device automatically detects a series of triggering events based on the schedule, and the output device is for outputting a unique timestamp in response to each of the triggering events.

4. The apparatus of claim 3, wherein the schedule has regular intervals.

5. The apparatus of claim 3, wherein the schedule has irregular intervals.

6. The apparatus of claim 2, wherein the schedule is predetermined.

7. The apparatus of claim 6, wherein the schedule has predetermined times.

8. The apparatus of claim 2, further comprising an input device coupled to the computing device for receiving input signals representing the schedule, wherein the computing device loads the schedule into the memory based on the input signals.

9. The apparatus of claim 8, wherein the input signals received by the input device includes a request encrypted using a key for loading the schedule.

10. The apparatus of claim 2, wherein the computing device is further programmed to modify the schedule in response to detection of a targeted event.

11. The apparatus of claim 10, wherein the computing device accelerates the schedule in response to the detection of the targeted event.

12. The apparatus of claim 1, further comprising means for automatically detecting a series of triggering events, and the output device is for outputting a unique timestamp in response to each of the triggering events.

13. The apparatus of claim 1, wherein the computing device is programmed to automatically detect the triggering event based on a previously output timestamp.

14. The apparatus of claim 1, wherein the output device includes a document production device, the triggering event is the production of the physical document by the document production device, and the timestamp is output to the physical document upon its production.

15. The apparatus of claim 1, wherein the output device includes a document production device, the document production device includes a certify button, and the timestamp is output upon manual activation of the certify button.

16. The apparatus of claim 15, wherein the document production device further includes an on-off timestamp button, and wherein automatic timestamp output on production of the physical document and manual timestamp output on manual activation of the certify button is selectable by actuating the on-off timestamp button.

17. The apparatus of claim 14, wherein the document production device is a printer and the timestamp is automatically output on printing of the physical document.

18. The apparatus of claim 17, wherein the printer is a computer printer.

19. The apparatus of claim 17, wherein the printer is a document printer.

20. The apparatus of claim 17, wherein the printer is a facsimile machine, the timestamp is automatically output on printing of a facsimile by the facsimile machine.

21. The apparatus of claim 17, wherein the printer is a photocopier, the timestamp is automatically output on printing of a photocopy by the photocopier.

22. The apparatus of claim 17, wherein the printer is a barcode printer, the timestamp automatically output on printing of a barcode by the barcode printer.

23. The apparatus of claim 1, further comprising a sensor for generating a sensed signal, wherein the timestamp is output in response to automatic detection of the triggering event based upon the sensed signal.

24. The apparatus of claim 23, wherein the sensed signal represents an event external to the apparatus, the timestamp occurring based on the external event.

25. The apparatus of claim 24, wherein the external event is a normal occurrence whose time of occurrence is to be recorded.

26. The apparatus of claim 25, wherein the external event is selected from the group consisting of entering an automated toll road and passing a checkpoint.

27. The apparatus of claim 24, wherein the external event is an abnormal occurrence whose time of occurrence is to be recorded.

28. The apparatus of claim 27, wherein the external event is selected from the group consisting of leaving an authorized operating area and having an accident.

29. The apparatus of claim 23, wherein the sensor includes a GPS receiver.

30. The apparatus of claim 1, further comprising an electromechanical circuit for taking an additional action upon the automatic detection of the triggering event.

31. The apparatus of claim 30, wherein the electromechanical circuit is for automatically cutting-off a vehicle engine upon the detection of the triggering event.

32. The apparatus of claim 1, wherein the triggering event involves receiving a broadcast signal.

33. A method for secure document timestamping, comprising the steps of:

generating a representation of the time;

performing a cryptographic operation on the representation of the time to produce a timestamp;

automatically detecting a triggering event; and

outputting the timestamp in an optically detectable form to a physical document in response to the automatic detection of the triggering event;

at least one of the steps of generating and performing being performed in a tamper-resistant environment.

34. The method of claim 33, wherein the step of automatically detecting the triggering event includes accessing a schedule.

35. The method of claim 34, wherein the step of automatically detecting the triggering event includes detecting a series of triggering events using the schedule, the outputting step including outputting a timestamp for each of the triggering events.

36. The method of claim 34, further comprising the step of modifying the schedule in response to detection of a targeted event.

37. The method of claim 33, wherein the step of automatically detecting the triggering event includes responding to a previously output timestamp.

38. The method of claim 33, further comprising the step of producing the physical document, wherein the step of automatically detecting the triggering event includes detecting the production of the physical document, and the step of outputting the timestamp includes outputting the timestamp upon the detected production of the physical document.

39. The method of claim 38, wherein the step of producing the physical document includes the step of printing a facsimile, and the step of outputting the timestamp includes automatically outputting the timestamp on printing the facsimile.

40. The method of claim 38, wherein the step of producing the physical document includes the step of printing a photocopy, and the step of outputting the timestamp includes automatically outputting the timestamp on printing the photocopy.

41. The method of claim 38, wherein the step of producing the physical document includes the step of printing a barcode, and the step of outputting the timestamp includes automatically outputting the timestamp on printing the barcode.

42. The method of claim 33, further comprising the step of receiving a sensed signal, wherein the step of outputting the timestamp is performed in response to automatic detection of the triggering event based on the sensed signal.

43. The method of claim 42, wherein the step of receiving a sensed signal includes receiving a signal representative of an occurrence of a normal event.

44. The method of claim 42, wherein the step of receiving a sensed signal includes receiving a signal representative of an occurrence of an abnormal event.

45. The method of claim 33, further comprising the step of taking an additional action upon the automatic detection of the triggering event.

46. An apparatus for secure document timestamping, comprising:

means for generating a representation of the time;

means for performing a cryptographic operation on the representation of the time to produce a timestamp;

means for automatically detecting a triggering event; and

means for outputting the timestamp in an optically detectable form to a physical document in response to the automatic detection of the triggering event;

means for locating at least one of the generating means and the performing means in a tamper-resistant environment.

47. An apparatus for secure document timestamping, comprising:

a time generator for generating representations of the time;

a computing device coupled to receive the representations of the time from the time generator and programmed to perform a series of cryptographic operations on the representations of the time to produce timestamps;

an output device, coupled to the computing device, for outputting the timestamps in optically detectable form in response to a predetermined schedule; and

means for rendering at least one of the time generator and the computing device resistant to tampering.

48. An apparatus for secure document timestamping, comprising:

a time generator for generating a representation of the time;

a computing device coupled to receive the representation of the time from the time generator and programmed to perform a cryptographic operation on the representation of the time to produce a timestamp;

a computer printer, coupled to the computing device, for printing a printed document and for automatically outputting the timestamp in optically detectable form to the printed document on printing the printed document; and

means for rendering at least one of the time generator and the computing device resistant to tampering.

49. An apparatus for secure document timestamping, comprising:

a time generator for generating a representation of the time;

a computing device coupled to receive the representation of the time from the time generator and programmed to perform a cryptographic operation on the representation of the time to produce a timestamp;

a facsimile machine, coupled to the computing device, for printing a facsimile and for automatically outputting the timestamp in optically detectable form to the facsimile upon printing of the facsimile; and

means for rendering at least one of the time generator and the computing device resistant to tampering.

50. An apparatus for secure document timestamping, comprising:

a time generator for generating a representation of the time;

a computing device coupled to receive the representation of the time from the time generator and programmed to perform a cryptographic operation on the representation of the time to produce a timestamp;

a photocopier, coupled to the computing device, for printing a photocopy and for automatically outputting the timestamp in optically detectable form to the photocopy upon printing of the photocopy; and

means for rendering at least one of the time generator and the computing device resistant to tampering.