System and method for providing fault tolerant transcriptions over an unsecured communication channel

• US 6,199,055 B1
• Filed: 11/05/1997
• Issued: 03/06/2001
• Est. Priority Date: 11/05/1997
• Status: Expired due to Term

• Current Assignee: Stamps.com, Inc.
• Original Assignee: E-Stamp Corporation (LTWC Corp.)
• Inventors: Desai, Manish, Hinh, Ken D., Husain, Mohammas A., Kara, Salim G., Pagel, Martin J.
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US08/965,069
• Time in Patent Office: 1,217 Days
• Field of Search: 371/31, 395/181, 395/182.13, 395/182.17, 705/35, 705/39, 705/41, 705/400, 705/405, 714/2, 714/15, 714/19, 714/747, 902/38, 902/41
• US Class Current: 705/405
• CPC Class Codes: G06Q 20/00 Payment architectures, schemes or protocols apparatus for performing or posting payment transactions G07F7/08, G07F19/00; electronic cash registers G07G1/12
• CPC Class Codes: G06Q 20/10 specially adapted for electronic funds transfer [EFT] systems; specially adapted for home banking systems
• CPC Class Codes: G07B 2017/00153 for sending information
• CPC Class Codes: G07F 19/20 Automatic teller machines [ATMs]
• CPC Class Codes: G07F 19/201 Accessories of ATMs

Abstract

A system and method for conducting secure fault tolerant transactions, such as financial transaction, remotely is disclosed. The transactions are conducted utilizing a portable processor device which is initialized and authorized according to the present invention. Thereafter, the portable processor operates to conduct transactions involving information exchange through unsecured communication paths according to a predetermined protocol. The protocol includes the use of atomic transactions within the portable processor device.

Claims

1. A method for predictably completing an electronic transaction conducted at least in part on a first system and a second system, said method comprising the steps of:

interfacing said first system with said second system, said interface providing data communication between said first system and said second system suitable for conducting said transaction;

initiating a current transaction through information communication between said first and second systems;

determining exclusively under control of said first system whether a previous transaction in so far as accomplished on said first system has successfully completed;

restoring a previous state of said first system if said previous transaction has not successfully completed;

updating a register accessible only to said first system upon commencement of said current transaction in so far as accomplished on said first system to indicate said current transaction has commenced;

updating a memory accessible only to said first system to store a copy of any information which is to be altered by said current transaction; and

updating said register upon completion of said current transaction in so far as accomplished on said first system to indicate said current transaction has concluded.

2. The method of claim 1, further comprising the step of:

attempting to accomplish said previous transaction if said previous transaction has not successfully completed, wherein said restoring step is performed after said attempting step if said attempting step is not able to accomplish said previous transaction.

3. The method of claim 1, wherein said first system is a portable postage vault and said second system is a general purpose processor based system.

4. The method of claim 3, wherein said current transaction is a postage value credit deduction transaction transferring postage credit from said portable postage vault to said second system for printing of a meter stamp by said second system.

5. The method of claim 3, wherein said current transaction is a postage value credit incrementing transaction transferring postage credit from said second system to said portable postage vault.

6. The method of claim 1, wherein said second system comprises:

a host system disposed locally to said first system and coupled to said first system through an unsecured data path.

7. The method of claim 6, wherein said unsecured data path includes a one wire bus.

8. The method of claim 6, wherein said second system further comprises:

a remote system coupled to said host system through an unsecured data path.

9. The method of claim 8, wherein said second mentioned data path is selected from the group consisting of the Internet, a wide area network, a local area network, and a public switched network.

10. The method of claim 8, further comprising the steps of:

determining exclusively under control of said remote system whether a previous transaction in so far as accomplished on said remote system has successfully completed;

interrupting said transaction if said previous transaction in so far as accomplished on said remote system has not successfully completed;

updating a register accessible only to said remote system upon commencement of said transaction in so far as accomplished on said remote system to indicate said transaction has commenced;

updating a memory accessible only to said remote system to store a copy of any information which is to be altered by said transaction;

updating said register upon completion of said transaction in so far as accomplished on said remote system to indicate said transaction has concluded.

11. The method of claim 1, further comprising the steps of:

executing at least one of a plurality of predefined sets of procedures on said first system, wherein said predefined sets of procedures are each defined to interact producing only two states upon execution, the first said state being successful completion of the set of procedures and the second said state being reversal of incomplete execution of the set of procedures.

12. The method of claim 11, wherein execution of said predefined set of procedures comprises the steps of:

determining whether previous execution of a predefined set of procedures of said plurality has concluded;

restoring a previous state of said first system if said previous execution has not concluded;

changing a register upon commencement of said execution of said predefined set of procedures to reflect commencement;

copying information which is to be altered by execution of said predefined set of procedures to a protected memory area; and

changing said register upon completion of said execution of said predefined set of procedures to reflect completion.

13. The method of claim 11, wherein execution of said predefined set of procedures further comprises the step of:

changing said register upon reaching a preselected intermediate point in said execution of said predefined set of procedures.

14. The method of claim 11, wherein procedures of said plurality of predefined sets of procedures are atomic transactions internal to said first system and other procedures of said predefined sets of procedures are atomic transactions external to said first system.

15. The method of claim 14, wherein said current transaction includes executing at least one of said internal atomic transactions and at least one of said external atomic transactions.

16. The method of claim 11, wherein execution of said predefined set of procedures comprises the steps of:

generating a request corresponding to said transaction;

transmitting said request to a process operable to accomplish at least a portion of said transaction;

accepting a transaction command in response to transmission of said request;

generating a commit corresponding to acceptance of said transaction command; and

transmitting said commit to said process operable to accomplish at least a portion of said transaction.

17. The method of claim 16, wherein said process operable to accomplish at least a portion of said transaction is operable exclusively in said first system.

18. The method of claim 16, wherein said process operable to accomplish at least a portion of said transaction is operable exclusively external to said first system.

19. A system utilized in conducting electronic transactions adapted to conduct fault tolerant transactions, said system comprising:

a first processor based system coupled to a second processor based system via an unsecured data path;

wherein said first system includes;

an operating code providing a limited set of predefined commands, ones of said commands defining at least a portion of said transaction;

a CPU operating under control of said operating code;

a limited access non-volatile memory area, said memory area being accessible to devices external to said first system only under control of said CPU;

means for indicating a state of said first system, said indicating means being accessible only to said CPU;

means for storing information associated with a prior state of said first system, said storing means being accessible only to said CPU;

means for restoring said first system to said prior state through reference to said information associated with said prior state; and

means for interfacing with said second processor based system, said interface means providing data communication between said first system and said second system, said second system being external to said first system, wherein at least a portion of said transaction includes data communication between said first system and said second system through said interfacing means; and

wherein said second system includes;

a general purpose computer;

means for indicating a state of said first system; and

means for storing information associated with a prior state of said first system.

20. The system of claim 19, wherein said states indicated by said indicating means include at least one state selected from the group consisting of a transaction has commenced, a transaction has completed, and a transaction was unsuccessful.

21. The system of claim 19, wherein said states indicated by said indicating means are updated to indicate a predefined milestone in said transaction being reached.

22. The system of claim 19, wherein said first system is selected from the group consisting of a touch memory unit, a PCMCIA card, a smart card, and a smart disk.

23. The system of claim 19, wherein said unsecured data path includes a one wire bus.

24. The system of claim 19, wherein said second system further comprises:

a remote system coupled to said general purpose computer via an unsecured data path.

25. The system of claim 24, wherein said last mentioned data path is selected from the group consisting of the Internet, a wide area network, a local area network, and a public switched network.

26. The system of claim 24, wherein said transaction is a financial transaction and said remote system comprises means for dispensing monetary value to said first system, and wherein said first system comprises means for storing said monetary value in said memory area.

27. The system of claim 19, wherein at least one command of said limited set of predefined commands comprises:

an atomic transaction defining processing of said one command by said CPU to produce only two states, the first said state being successful completion of the command and the second said state being reversal of incomplete processing of the command.

28. The system of claim 27, wherein said atomic transaction comprises:

means operable upon completion of processing of said command for controlling said indicating means to indicate completion of processing said command in said indicating means.

29. The system of claim 27, wherein said atomic transaction further comprises:

means for generating a request corresponding to said transaction;

means for transmitting said request to a process operable to accomplish at least a portion of said transaction;

means for accepting a transaction command in response to transmission of said request;

means for generating a commit corresponding to acceptance of said transaction command; and

means for transmitting said commit to said process operable to accomplish at least a portion of said transaction.

30. The system of claim 29, wherein said process operable to accomplish at least a portion of said transaction is internal to said first processor based system.

31. The system of claim 29, wherein said process operable to accomplish at least a portion of said transaction is external to said first processor based system.

32. The system of claim 27, wherein said atomic transaction comprises:

means for controlling said storing means to store information associated with the state of said first processor at commencement of processing said command; and

means for controlling said indicating means to indicate commencement of processing said command in said indicating means.

33. The system of claim 32, wherein said atomic transaction further comprises:

a process to store an indication of accomplishing a predefined processing milestone of said command in said indicating means.

34. The system of claim 32, wherein said atomic transaction further comprises:

means for restoring said first processor to a previous state.

35. The system of claim 34, wherein said restoring means comprises:

means for determining if a previous command has completed processing through reference to said indicating means; and

means for copying information stored by said storing means to portions of said memory area previously associated with said copied information.

36. A method to provide only predefined conclusions to a transaction, said predefined conclusions providing for only two conclusion states, the first said state being successful completion of said transaction and the second said state being to roll back an incomplete transaction, said method comprising the steps of:

initializing a first processor based system to substantially permanently operate as a secure portable processor device, said initialization comprising the steps of;

defining only a limited number of predefined commands operable in said first system, at least one of said commands defining at least a portion of said transaction as fulfilled on said first system;

limiting access to non-volatile memory areas to restrict devices external to said first system from direct access to said memory areas;

identifying a register within said memory areas for use in indicating a state of said first system; and

identifying a previous state storage area within said memory areas for use in storing information associated with a prior state of said first system;

interfacing said first system with a second processor based system, said interface providing data communication between said first system and said second system;

initiating a current transaction through information communication between said first and second systems;

determining whether a previous transaction as fulfilled on said first system has concluded;

restoring a previous state of said first system utilizing information stored in said previous state storage area if said previous transaction has not concluded;

updating said register upon commencement of said current transaction to indicate said transaction has commenced;

updating said previous state storage area to store information stored in areas of said memory areas which are to be altered by said current transaction; and

updating said register upon completion of said current transaction to indicate said current transaction has concluded.

37. The method of claim 36, further comprising the step of:

updating said register upon reaching a predefined event in said transaction.

38. The method of claim 36, wherein at least one command of said limited set of predefined commands defines processing by said CPU to produce only two states upon execution of said command, the first said state being successful completion of the command and the second said state being reversal of incomplete processing of the command.

39. The method of claim 36, wherein execution of at least one command of said limited set of predefined commands comprises the steps of:

generating a first data packet indicating at least a portion of said transaction to be performed by a process;

communicating said first data packet to said process; and

accepting a second data packet from said process responsive to said first data packet when said at least a portion of said transaction is performed by said process.

40. The method of claim 39, wherein said at least one command of said limited set of predefined commands further comprises the steps of:

generating a third data packet indicating acceptance of said second data packet; and

communicating said third data packet to said process, wherein said process relies on said third data packet to determine said at least a portion of said transaction has been successfully performed.

41. The method of claim 36, wherein execution of at least one command of said limited set of predefined commands utilized to fulfill said transaction comprises the steps of:

determining whether a previous command has concluded;

restoring a previous state of said first system utilizing information stored in said previous state storage area if said previous command has not concluded;

updating said register upon commencement of said command to indicate said command has commenced;

updating said previous state storage area to store information stored in areas of said memory areas which are to be altered by said command;

updating said register upon completion of said command to indicate said command has concluded.

42. The method of claim 41, wherein execution of said at least one command further comprises the steps of:

updating said register upon reaching a predefined event in said command.

43. The method of claim 36, wherein said second system comprises:

a general purpose computer coupled to said first processor via an unsecured data path.

44. The method of claim 43, wherein said second system further comprises:

a remote system coupled to said general purpose computer via an unsecured data path.