Distributed protocol for secure communication of commercial transactions and decentralized network employing the protocol

• US 6,742,125 B1
• Filed: 11/13/1996
• Issued: 05/25/2004
• Est. Priority Date: 11/13/1996
• Status: Expired due to Term

• Current Assignee: Nokia of America Corporation (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Silberschatz, Abraham, Gabber, Eran
• Primary Examiner(s): Smithers, Matthew
• Application Number:
  US08/748,314
• Time in Patent Office: 2,750 Days
• Field of Search: 730/26, 730/27, 380/30, 705/39
• US Class Current: 726/4
• CPC Class Codes: G06Q 20/10 specially adapted for electronic funds transfer [EFT] systems; specially adapted for home banking systems
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions

Abstract

A protocol and system for securely communicating a financial transaction between a customer and a merchant and a distributed computer network employing the protocol or system. A central authority having a central authority private key K^s_ca assigns a customer account (“CACCT”) to the customer and a merchant account (“MACCT”) to the merchant. The customer has a customer public key K^p_c; the merchant has a merchant public key K_m. The protocol includes the steps of: (1) sending a quotation from the merchant to the customer, the quotation including the K^p_m, a K^s_ca-signed signature that is a function of the MACCT, an unsigned copy of a price and a K^s_m-signed signature that is a function of the MACCT and the price, (2) replying to the quotation by sending an order from the customer to the merchant, the order including the K^p_c, a K^s_ca, signed signature that is a function of the CACCT, an unsigned copy of the price and a K^s_c-signed signature that is a function of the CACCT, the MACCT and the price and (3) replying to the order by filling the order.

Claims

1. A protocol for securely communicating a financial transaction between a customer and a merchant, a central authority having a central authority private key K^s_ca and assigning a customer account (CACCT) to said customer and a merchant account (MACCT) to said merchant, said customer having a customer public key K^p_c, said merchant having a merchant public key K^p_m, said protocol comprising the steps of:

sending a quotation from said merchant to said customer, said quotation including said K^p_m, a K^s_ca-signed signature that is a function of said MACCT, an unsigned copy of a price and a merchant private key (K^s_m)-signed signature that is a function of said MACCT and said price;

receiving an order in response to said quotation, said order including said K^p_c, a K^s_ca-signed signature that is a function of said CACCT, an unsigned copy of said price and a customer private key (K^s_c)-signed signature that is a function of said CACCT, said MACCT and said price; and

replying to said order by filling said order.

2. The protocol as recited in claim 1 wherein said quotation further includes an unsigned sequence number unique to said merchant, said K^s_m-signed signature further being a function of said sequence number.

3. The protocol as recited in claim 1 wherein said order further includes an unsigned sequence number unique to said merchant, said K^s_c-signed signature further being a function of said sequence number.

4. The protocol as recited in claim 1 wherein said MACCT has an expiration date associated therewith, said quotation further including said expiration date, said K^s_m-signed signature further being a function of said expiration date.

5. The protocol as recited in claim 1 wherein said CACCT has an expiration date associated therewith, said order further including said expiration date, said K^s_c-signed signature further being a function of said expiration date.

6. The protocol as recited in claim 1 wherein said central authority has a central authority identification number (CAid), said quotation further including said CAid, said K^s_m-signed signature further being a function of said CAid.

7. The protocol as recited in claim 1 wherein said central authority has a central authority identification number (CAid) said order further including said CAid, said K^s_c-signed signature further being a function of said CAid.

8. The protocol as recited in claim 1 wherein signed information in said quotation and said order are signed by applying a secure, one-way hash function and an encryption function to information to be signed.

9. The protocol as recited in claim 1 wherein information in said quotation and said order are represented by alphanumeric characters.

10. The protocol as recited in claim 1 wherein said quotation and said order are encapsulated in Hypertext Transfer Protocol (HTTP) messages.

11. The protocol as recited in claim 1 wherein said MACCT and said price are verifiable by said customer.

12. The protocol as recited in claim 1 wherein said CACCT, said MACCT and said price are verifiable by said customer.

13. The protocol as recited in claim 1 wherein said order is an order for data to be delivered via a computer network.

14. The protocol as recited in claim 1 wherein said CACCT is an alias account.

15. The protocol as recited in claim 1 wherein said MACCT is an alias account.

16. The protocol as recited in claim 1 wherein a database associated with said merchant contains a list of CACCTS revoked by said central authority, said protocol further comprising the step of comparing said CACCT against said list of CACCTS revoked by said central authority.

17. The protocol as recited in claim 1 further comprising the steps of:

maintaining, by said merchant, a record of purchases by said customer; and

sending a message from said merchant to said central authority regarding said customer when said purchases exceed a predetermined maximum allowable amount.

18. The protocol as recited in claim 1 further comprising the steps of:

maintaining, by said merchant, a record of purchases and times of said purchases by said customer; and

sending a message from said merchant to said central authority regarding said customer when said purchases exceed a predetermined maximum allowable rate.

19. The protocol as recited in claim 1 further comprising the step of sending a message from said merchant to said central authority regarding said customer as a function of a uniformly distributed random number.

20. The protocol as recited in claim 1 further comprising an arbitration procedure, comprising the steps of:

including a field in said quotation that is a function of information that is a subject of said quotation;

sending an arbitration request from said customer to an arbiter, said arbitration request containing said quotation and said order;

sending an information request from said arbiter to said merchant, said information request requesting a copy of said information that is said subject of said quotation;

forwarding said information that is said subject of said quotation to said customer if said information correlates to said field;

repudiating said financial transaction if said merchant fails to respond to said information request; and

repudiating said financial transaction if said information fails to correlate to said field.

21. The protocol as recited in claim 1 wherein said order further includes a SCid and said merchant uses said SCid to verify said customer.

22. The protocol as recited in claim 1 wherein said quotation further includes a SMid and said customer uses said SMid to verify said merchant.

23. A system for securely communicating a financial transaction between a customer and a merchant, a central authority having a central authority private key K^s_ca and assigning a customer account (CACCT) to said customer and a merchant account (MACCT) to said merchant, said customer having a customer public key K^p_c, said merchant having a merchant public key K^p_m, said system comprising:

a quotation transmission controller, associated with said merchant, that sends a quotation to said customer, said quotation including said K^p_m, a K^s_ca-signed signature that is a function of said MACCT, an unsigned copy of a price and a merchant private key (K^s_m)-signed signature that is a function of said MACCT and said price;

an order reception controller, associated with said merchant, that receives an order from said customer in response to said quotation, said order including said K^p_c, a K^s_ca-signed signature that is a function of said CACCT, an unsigned copy of said price and a customer private key (K^s_c)-signed signature that is a function of said CACCT, said MACCT and said price; and

an order confirmation controller that confirms said order to said customer.

24. The system as recited in claim 23 wherein said quotation further includes an unsigned sequence number unique to said merchant, said K^s_m-signed signature further being a function of said sequence number.

25. The system as recited in claim 23 wherein said order further includes an unsigned sequence number unique to said merchant, said K^s_c-signed signature further being a function of said sequence number.

26. The system as recited in claim 23 wherein said MACCT has an expiration date associated therewith, said quotation further including said expiration date, said K^s_m-signed signature further being a function of said expiration date.

27. The system as recited in claim 23 wherein said CACCT has an expiration date associated therewith, said order further including said expiration date, said K^s_c-signed signature further being a function of said expiration date.

28. The system as recited in claim 23 wherein said central authority has a central authority identification number (CAid), said quotation further including said CAid, said K^s_m-signed signature further being a function of said CAid.

29. The system as recited in claim 23 wherein said central authority has a central authority identification number (CAid), said order further including said CAid, said K^s_c-signed signature further being a function of said CAid.

30. The system as recited in claim 23 wherein signed information in said quotation and said order are signed by applying a secure, one-way hash function and an encryption function to information to be signed.

31. The system as recited in claim 23 wherein said quotation transmission controller and said order reception controller represent information in said quotation and said order by alphanumeric characters.

32. The system as recited in claim 23 wherein said quotation transmission controller and said order reception controller encapsulate said quotation and said order in Hypertext Transfer Protocol (HTTP) messages.

33. The system as recited in claim 23 wherein said customer verifies said MACCT and said price.

34. The system as recited in claim 23 wherein said merchant verifies said CACCT, said MACCT and said price.

35. The system as recited in claim 23 wherein said order is an order for data to be delivered via a computer network.

36. The system as recited in claim 23 wherein said CACCT is an alias account.

37. The system as recited in claim 23 wherein said MACCT is an alias account.

38. The system as recited in claim 23 wherein a database associated with said merchant contains a list of CACCTS revoked by said central authority, said order reception controller comparing said CACCT against said list of CACCTS revoked by said central authority.

39. The system as recited in claim 23 wherein said merchant maintains a record of purchases by said customer and said system further comprises a purchase reporting controller that sends a message from said merchant to said central authority regarding said customer when said purchases exceed a predetermined maximum allowable amount.

40. The system as recited in claim 23 wherein said merchant maintains a record of purchases and times of said purchases by said customer and said system further comprises a purchase reporting controller that sends a message from said merchant to said central authority regarding said customer when said purchases exceed a predetermined maximum allowable rate.

41. The system as recited in claim 23 further comprising a purchase reporting controller that sends a message from said merchant to said central authority regarding said customer as a function of a uniformly distributed random number.

42. The system as recited in claim 23 wherein said quotation further includes a field that is a function of information that is a subject of said quotation, said system further comprising an arbitration controller that sends a copy of said information that is said subject of said quotation.

43. The system as recited in claim 23 wherein said quotation further includes a SMid and said customer uses said SMid to verify said merchant.

44. The system as recited in claim 23 wherein said order further includes a SCid and said merchant uses said SCid to verify said customer.