Simultaneous electronic transactions with visible trusted parties

• US 5,553,145 A
• Filed: 08/04/1995
• Issued: 09/03/1996
• Est. Priority Date: 03/21/1995
• Status: Expired due to Term

• Current Assignee: DocuSign Incorporated
• Original Assignee: Silvia Micali
• Inventors: Micali, Silvia
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/511,518
• Time in Patent Office: 396 Days
• Field of Search: 380/25, 380/30
• US Class Current: 380/30
• CPC Class Codes: G06F 2211/008 Public Key, Asymmetric Key, Asymmetric Encryption
• CPC Class Codes: G06F 2211/009 Trust
• 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 20/02 involving a neutral party, e.g. certification authority, notary or trusted third party [TTP]
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/3825 Use of electronic signatures
• CPC Class Codes: G06Q 20/388 using mutual authentication without cards, e.g. challenge-response
• CPC Class Codes: G06Q 20/389 Keeping log of transactions for guaranteeing non-repudiation of a transaction
• CPC Class Codes: G06Q 20/401 Transaction verification
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G06Q 50/188 Electronic negotiation
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• 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 2463/102 applying security measure for e-commerce data processing systems or methods, specially adapted for e-commerce G06Q30/00
• CPC Class Codes: H04L 51/23 Reliability checks, e.g. acknowledgments or fault reporting
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/0841 involving Diffie-Hellman or related key agreement protocols
• CPC Class Codes: H04L 9/085 : Secret sharing or secret splitting, e.g. threshold schemes
• CPC Class Codes: H04L 9/321 : involving a third party or a trusted authority
• CPC Class Codes: H04L 9/3247 : involving digital signatures

Abstract

A number of electronic communications methods are described involving a first and a second party, with assistance from at least a trusted party, enabling electronic transactions in which the first party has a message for the second party. The first party, the second party and the trusted party undertake an exchange of transmissions, at least one of which occurs electronically and in an encrypted manner, such that if all transmissions reach their destinations the second party only receives the message if the first party receives at least one receipt. Preferably, the identity of the first party is temporarily withheld from the second party during the transaction. At least one receipt received to the first party enables the first party to prove the content of the message received by the second party.

Claims

1. An electronic communications method between a first and a second party, with assistance from at least a trusted party, enabling an electronic transaction in which the first party has a message for the second party, comprising the steps of:

having the first party transmit to the trusted party a custom version of the message intelligible to the second party but not by the trusted party;

in response, having the trusted party verify that the first party transmitted the custom version of the message and that the second party is the intended recipient thereof;

having the trusted party transmit to the second party information that identifies the first party and from which the second party can retrieve the message; and

having the trusted party transmit to the first party a sending receipt indicating that the message has been transmitted to the second party;

wherein at least one of the transmissions is carried out electronically and the first party does not communicate an encryption of the message directly to the second party to facilitate said electronic transaction.

2. The electronic communications method as described in claim 1 wherein the first party generates the custom version of the message at least by encrypting the message with a key associated with the second party.

3. The electronic communications method as described in claim 1 wherein the first party generates the custom version of the message at least by encrypting a value with a key associated with the trusted party, the value including the encryption of the message with a key associated with the second party.

4. The electronic communications method as described in claim 3 wherein the value includes other information selected from the following:

an identifier of the first party, an identifier of the second party, and an identifier signifying that the custom value is part of an electronic transaction.

5. The electronic communications method as described in claim 1 wherein the information that the trusted party transmits to the second party includes at least an encryption of the message with a key associated with the second party.

6. The electronic communications method as described in claim 5 wherein the information that the trusted party transmits to the second party includes an identifier signifying that the information is part of an electronic transaction and information indicating that the message was sent by the first party.

7. The electronic communications method as described in claim 1 wherein the sending receipt includes a digital signature of the trusted party.

8. The electronic communications method as described in claim 1 wherein the sending receipt enables the first party to prove the content of the message.

9. The electronic communications method as described in claim 8 wherein at least one transmission is encrypted with a key associated with a recipient of that transmission.

10. The electronic communications method as described in claim 7 wherein each transmission is encrypted with a key associated with a recipient of that transmission.

11. The electronic communications method as described in claim 7 wherein the trusted party digitally signs information selected from the following:

an identifier of the first party, an identifier the second party, an identifier signifying that the custom value is part of an electronic transaction, an encryption of the message with a key associated with the second party, information identifying a time when the trusted party transmitted the sending receipt, and information identifying a time when the trusted party received the custom version of the message.

12. The electronic communications method as described in claim 11 wherein the sending receipt enables the first party to prove the content of the message.

13. The electronic communications method as described in claim 1 wherein the at least one of the first party, the second party and the trusted party cooperates with a plurality of agents in a predetermined manner to assist in effecting the electronic transaction.

14. The electronic communications method as described in claim 13 wherein a plurality of agents relative to one of the first party, the second party and the trusted party hold shares of a secret key of that party.

15. The electronic communications method as described in claim 13 wherein the trusted party does not assist the transaction if there is not a plurality of agents holding shares of a key associated with the second party.

16. The electronic communications method as described in claim 1 wherein the information transmitted from the trusted party to the second party does not identify the first party in at least one of the transmissions to the second party.

17. The electronic communications method as described in claim 1 further including the steps of:

requesting the second party to transmit a return receipt of the message;

if the second party does not transmit the return receipt within a given period of time, having the message sent again to the second party by a non-electronic return receipt method.

18. The electronic communications method as described in claim 17 wherein at least one return receipt indicates the contents of the message.

19. The electronic communications method as described in claim 1 wherein the trusted party does not issue a receipt considered to be valid unless the custom version of the message is received by the trusted party within a given time.

20. The electronic communications method as described in claim 11 where the trusted party does not issue a receipt considered to be valid unless the custom version of the message is received by the trusted party within a given time.

38. The electronic communications method as described in claim 1 wherein the message is a bid and the electronic transaction is an auction.

39. The electronic communications method as described in claim 1 wherein the message is the first party'"'"'s commitment to a contract and the electronic transaction is a contract closing.

21. An electronic communications method between a first and a second party, with assistance from at least a trusted party, enabling an electronic transaction in which the first party has a message for the second first party, comprising the steps of:

having the first party transmit to the trusted party a custom version of the message intelligible to the second party but not by the trusted party;

in response, having the trusted party verify that the first party transmitted the custom version of the message and that the second party is the intended recipient thereof;

having the trusted party transmit to the second party first information which determines the message but retains the message and the identity of the first party hidden from the second party;

determining whether within a given time the second party transmits to the trusted party a return receipt indicating that the second party received the transmission of the first information from the trusted party; and

if the second party transmits the return receipt to the trusted party, having the trusted party (i) transmit to the second party second information from which the second party, using the first and second information, can retrieve the message, and (ii) transmit to the first party a receipt that the second party has received the message;

wherein at least one of the transmissions is carried out electronically and the first party does not communicate an encryption of the message directly to the second party to facilitate the electronic transaction.

22. The electronic communications method as described in claim 21 wherein the trusted party also transmits to the first party a sending receipt for the message.

23. The electronic communications method as described in claim 21 wherein the second information also enables the second party to prove the identity of the first party and the content of the message, and at least one receipt proves the content of the message and the identity of the second party.

24. The electronic communications method as described in claim 21 wherein the first party generates the custom version of the message at least by encrypting the message with a key associated with the second party.

25. The electronic communications method as described in claim 21 wherein the first party generates the custom version of the message by encrypting a value with a key associated with the trusted party, the value including the encryption of the message with a key associated with the second party.

26. The electronic communications method as described in claim 25 wherein the value includes other information selected from the following:

an identifier of the first party, an identifier of the second party, and an identifier signifying that the custom value is part of an electronic transaction, and an identifier signifying a time of transmission.

27. The electronic communications method as described in claim 21 wherein the second party must transmit the return receipt to the trusted party within a predetermined time period in order for the electronic transaction to be valid.

28. The electronic communications method as described in claim 21 wherein after the trusted party verifies that the first party transmitted the custom version of the message, the trusted party transmits to the first party a guarantee that the custom version of the message has been sent to the second party.

29. The electronic communications method as described in claim 21 wherein all of the transmissions are carried out electronically.

30. The electronic communications method as described in claim 21 wherein the one of the first party, the second party and the trusted party cooperates with a plurality of agents in a predetermined manner to assist in effecting the electronic transaction.

31. The electronic communications method as described in claim 30 wherein a plurality of agents relative to one of the first party, the second party and the trusted party hold shares of a secret key of that party.

32. The electronic communications method as described in claim 31 wherein the trusted party does not assist the transaction if there is not a plurality of agents holding shares of a key associated with the second party.

33. The electronic communications method as described in claim 21 wherein if the second party does not receive the second information in a given period of time, having the second party take additional steps to initiate a transaction that guarantees that the second party receives the message.

49. The electronic communications method as described in claim 21 wherein the first party transmits to the trusted party additional information before the trusted party transmits the second information to the second party.

34. An electronic communications method between a first and a second party, with assistance from at least a trusted party, enabling an electronic transaction in which the first party has a message for the second party but wherein the first party does not communicate an encryption of the message directly to the second party to facilitate the electronic transaction, comprising the steps of:

having the first party transmit to the trusted party a version of the message intelligible to the second party but not by the trusted party;

in response, having the trusted party verify that the first party transmitted the version of the message and that the second party is the intended recipient thereof;

having the trusted party transmit to the second party first information which determines the message but retains the message and the identify of the first party hidden from the second party;

in response, determining whether within a predetermined time the second party transmits to the trusted party a return receipt indicating that the second party received the transmission of the first information from the trusted party;

if the second party does not transmit the return receipt within the predetermined time, having the trusted party take action to deliver the message to the second party in a way to guarantee the generation of the return receipt.

35. The electronic communications method as described in claim 34 wherein the action taken by the trusted party includes having the message sent to the second party by a non-electronic return receipt method.

36. The electronic communications method as described in claim 34 wherein the trusted party also transmits to the first party at least one receipt for the message.

37. The electronic communications method as described in claim 36 wherein the receipt obtained by the first party enables the first party to prove the content of the message.

40. An electronic communications method between a first and a second party, with assistance from at least a trusted party, enabling an electronic transaction in which the first party has a message for the second party, comprising the step of:

having the first party, the second party and the trusted party undertake an exchange of transmissions, at least one of which occurs electronically and in an encrypted manner, but where the first party does not communicate an encryption of the message directly to the second party to facilitate the electronic transaction, such that if all transmissions reach their destinations the second party only receives the message if the first party receives at least one receipt.

41. The electronic communications method as described in claim 40 wherein at least one receipt received by the first party enables the first party to prove the content of the message received by the second party.

42. The electronic communications method as described in claim 41 wherein the one receipt is a return receipt produced by the second party.

43. The electronic communications method as described in claim 42 wherein the trusted party delivers the message to the second party by a non-electronic return receipt method if the second party does not deliver electronically a return receipt within a given amount of time.

44. The electronic communications method as described in claim 40 wherein the one of the first party, the second party and the trusted party cooperates with a plurality of agents in a predetermined manner to assist in effecting the electronic transaction.

45. The electronic communications method as described in claim 44 wherein a plurality of agents relative to one of the first party, the second party and the trusted party hold shares of a secret key of that party.

46. The electronic communications method as described in claim 45 wherein the trusted party does not assist the transaction if there is not a plurality of agents holding shares of a key associated with the second party.

47. The electronic communications method as described in claim 40 wherein the message is a bid and the electronic transaction is an auction.

48. The electronic communications method as described in claim 40 wherein the message is the first party'"'"'s commitment to a contract and the electronic transaction is a contract closing.