Apparatus and method for proving transaction between users in network environment

• US 6,470,448 B1
• Filed: 03/31/1997
• Issued: 10/22/2002
• Est. Priority Date: 10/30/1996
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Iwase, Shoko, Torii, Satoru, Ono, Etsuo, Komura, Masahiro, Kuroda, Yasutsugu
• Primary Examiner(s): Smithers, Matthew
• Application Number:
  US08/831,328
• Time in Patent Office: 2,031 Days
• Field of Search: 380/23, 380/24, 380/25, 705/26, 705/37, 705/39, 705/44, 705/64-68, 705/67, 705/75, 705/80, 705/76, 713/170, 713/178, 713/176
• US Class Current: 713/176
• 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: H04L 9/321 involving a third party or a trusted authority
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

The digital signatures of users A and B are created for a transaction document which states the contents of a transaction between the users A and B, and they are sent to a transaction proof device of a notary public being a third party, together with the transaction document. Thus, the users A and B and the notary public share information, and the notary public can objectively prove the transactional contents, etc.

Claims

1. A transaction proof apparatus for processing information on a transaction which is carried on between at least two users, comprising:

a communication device, connected to a communication network, receiving from the network digital signature data of a first user and digital signature data of a second user for transaction document data which contains information on the transaction between the first and second users, the digital signature data of the first user and the digital signature data of the second user indicating approval for the information on the transaction;

a processing device verifying the digital signature data of said first user and the digital signature data of said second user and affixing a digital signature of a third party to data containing at least one of the digital signature data of said first user and the digital signature data of said second user, thereby to generate digital signature data of the third party;

a storage device storing therein said transaction document data, said digital signature data of said first user, said digital signature data of said second user, and said digital signature data of the third party; and

a proving device proving in response to a request that the transaction was carried out between the first and second users by using data stored in the storage device,

wherein said communication device sends the digital signature data of the third party to the first and second users through the network, thereby a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the transaction proof apparatus and the first and second users.

2. A transaction proof apparatus according to claim 1, wherein:

said communication device further receives the transaction document data from said network, and

said processing device verifies said digital signature data of said first user and said digital signature data of said second user by use of said transaction document data and stores said transaction document data in said storage device together with said digital signature data of said first user and said digital signature data of said second user.

3. A transaction proof apparatus according to claim 2, further comprising:

a date-and-time issuance device issuing date-and-time information which expresses at least one of date and time of said transaction, wherein

said communication device receives said transaction document data which contain the date-and-time information, and

said processing device checks if said date-and-time information contained in said transaction document data agrees with the date-and-time information issued by said date-and-time issuance device.

4. A transaction proof apparatus according to claim 2, further comprising an identifier issuance device for issuing identifier information of said transaction, wherein:

said communication device receives said transaction document data which contain the identifier information, and

said processing device checks if said identifier information contained in said transaction document data agrees with the identifier information issued by said identifier issuance device.

5. A transaction proof apparatus according to claim 2, wherein:

said communication device receives a request for reference to said transaction document data from said network,

said processing device obtains said transaction document data from said storage device in compliance with the reference request, and

said communication device sends contents of said transaction document data to a source of said reference request through said network.

6. A transaction proof apparatus according to claim 1, wherein said communication device sends said digital signature data of said third party to said first and second users through said network.

7. A transaction proof apparatus according to claim 1, wherein:

said communication device further receives a digital signature of an agreeing party for the transaction document data from said network, and

said processing device stores the digital signature of the agreeing party in said storage device together with said digital signature data of said first user and said digital signature data of said second user.

8. A transaction proof apparatus according to claim 1, wherein:

said communication device receives an encrypted digital signature data of said first user and an encrypted digital signature data of said second user, and

said processing device decrypts the encrypted digital signature data of said first and second users and thereafter verifies the decrypted digital signature data.

9. A transaction proof apparatus for processing information on a transaction which is carried on between at least two users, comprising:

a communication device, connected to a communication network, receiving from the network digital signature data of a second user created for digital signature data of a first user for transaction document data which contains information on the transaction between the first and second users, the digital signature data of the first user and the digital signature data of the second user indicating approval for the information on the transaction;

a processing device verifying the digital signature data of said second user and affixing a digital signature of a third party to data containing the digital signature data of said second user, thereby to generate digital signature data of the third party;

a storage device storing said transaction document data, said digital signature data of said second user, and said digital signature data of the third party therein; and

a proving device proving in response to a request that the transaction was carried out between the first and second users by using data stored in the storage device,

wherein said communication device sends the digital signature data of the third party to the first and second users through the network, thereby a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the transaction proof apparatus and the first and second users.

10. A transaction proof apparatus for processing information on a transaction which is carried on between at least two users, comprising:

a communication device, connected to a communication network, receiving from the network transaction information of a first user and transaction information of a second user which contains information on the transaction between the first and second users, the transaction information of the first user and the transaction information of the second user indicating approval for the information on the transaction;

a processing device confirming that the transaction information of said first user and the transaction information of said second user having identical contents and affixing a digital signature of a third party to data containing at least one of the transaction information of said first user and the transaction information of said second user, thereby to generate digital signature data of the third party;

a storage device storing the transaction information of said first and second users and said digital signature data of the third party therein; and

a proving device proving in response to a request that the transaction was carried out between the first and second users by using data stored in the storage device,

wherein said communication device sends the digital signature data of the third party to the first and second users through the network, thereby a combination of the transaction information of the first user, the transaction information of the second user, and the digital signature data of the third party is retained by the transaction proof apparatus and the first and second users.

11. A terminal device for processing information on a transaction which is carried on between at least two users, comprising:

a processing device creating digital signature data of a first user for transaction document data which contains information on the transaction between the first and a second user, the digital signature data of the first user indicating approval for the information on the transaction;

a communication device, connected to a communication network, transmitting the transaction document data and the digital signature data of said first user to a third party through the network, and receiving digital signature data of the second user for the transaction document data which have been verified with the transaction document data by the third party and digital signature data of the third party for data which contain at least one of the digital signature data of said first user and the digital signature data of said second user, from said third party through said network, the digital signature data of the second user indicating approval for the information on the transaction; and

a storage device storing the transaction document data, the digital signature data of said first user, the digital signature data of said second user, and the digital signature data of the third party,

wherein a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

12. A terminal device according to claim 11, wherein said communication device transmits said transaction document data to said third party through said network, receives said digital signature data of said second user verified with said transaction document data by said third party, and stores said transaction document data in said storage device together with said digital signature data of said first user and said digital signature data of said second user.

13. A terminal device according to claim 13, wherein

said processing device verifies the digital signature data of said third party and stores the verified data in said storage device.

14. A terminal device for processing information on a transaction which is carried on between at least two users, comprising:

a processing device creating digital signature data of a first user for transaction document data which contains information on the transaction between the first user and a second user, the digital signature data of the first user indicating approval for the information on the transaction;

a communication device, connected to a communication network, receiving digital signature data of the second user for the transaction document data from said second user through the network, digital signature data of the second user indicating approval for the information on the transaction, transmitting the digital signature data of said first user and the digital signature data of said second user to a third party through said network, and receiving digital signature data of the third party for data which contains at least one of the digital signature data of said first user and the digital signature data of said second user from the network; and

a storage device storing said transaction document data, said digital signature data of said first user, said digital signature data of said second user, and the digital signature data of the third party,

wherein a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

15. A terminal device according to claim 14, wherein

said processing device verifies the digital signature data of said third party and stores verified data in said storage device.

16. A terminal device for processing information on a transaction which is carried on between at least two users, comprising:

a processing device creating transaction information of a first user which contains information on the transaction between said first user and a second user, the transaction information of the first user indicating approval for the information on the transaction;

a communication device, connected to a communication network, transmitting the transaction information of said first user to a third party through the network, receiving transaction information of said second user and digital signature data of the third party for data which contains at least one of the transaction information of said first user and the transaction information of said second user, from said third party through said network, the transaction information of the second user indicating approval for the information on the transaction; and

a storage device storing the received transaction information and the digital signature data of the third party,

wherein a combination of the transaction information of the first user, the transaction information of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

17. A terminal device for processing information on a transaction which is carried on between at least two users, comprising:

a processing device creating transaction information of a first user which contains information on the transaction between said first user and a second user, the transaction information of the first user indicating approval for the information on the transaction;

a communication device, connected to a communication network, receiving transaction information of said second user from said second user through the network, the transaction information of the second user indicating approval for the information on the transaction, transmitting the transaction information of said first user and the transaction information of said second user to a third party through said network, and receiving digital signature data of the third party for data which contains at least one of the transaction information of said first user and the transaction information of said second user from the network; and

a storage device storing said transaction information of said first user, the transaction information of said second user, and the digital signature data of the third party,

wherein a combination of the transaction information of the first user, the transaction information of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

18. A transaction proof system for processing information on a transaction which is carried on between at least two users, comprising:

a first creation device creating digital signature data of a first user for transaction document data which contains information on the transaction between the first user and a second user, the digital signature data of the first user indicating approval for the information on the transaction;

a second creation device creating digital signature data of the second user for the transaction document data, the digital signature data of the second user indicating approval for the information on the transaction;

a communication device, connected to a communication network, receiving the digital signature data of said first user and the digital signature data of said second user from the network;

a processing device verifying said digital signature data of said first user and said digital signature data of said second user;

a third creation device creating digital signature data of the third party for data which contains at least one of the digital signature data of said first user and the digital signature data of said second user;

a first storage device, to be referred to by said first user, storing said digital signature data of said first user, said digital signature data of said second user, and the digital signature data of the third party therein as a guarantee of the transaction;

a second storage device, to be referred to by said second user, storing said digital signature data of said first user, said digital signature data of said second user, and the digital signature data of the third party therein as a guarantee of the transaction;

a third storage device, to be referred to by a third party, storing said digital signature data of said first user, said digital signature data of said second user, and the digital signature data of the third party therein in proof of the transaction; and

a proving device proving in response to a request that the transaction was carried out between the first user and the second user, by using data stored in said third storage device.

19. A computer-readable storage medium which, when used by a computer for processing information on a transaction that is carried on between at least two users, causes the computer to perform the processes of:

receiving from a communication network, digital signature data of a first user and digital signature data of a second user for transaction document data which contains information on the transaction between the first and second users, the digital signature data of the first user and the digital signature data of the second user indicating approval for the information on the transaction;

verifying the digital signature data of said first user and the digital signature data of said second user and affixing a digital signature of a third party to data containing the digital signature data of said second user, thereby to generate digital signature data of the third party;

storing said transaction document data, said digital signature data of said first user, said digital signature data of said second user, and said digital signature data of the third party therein; and

proving in response to a request that the transaction was carried out between the first user and the second user, by using the stored data,

wherein the digital signature data of the third party is sent to the first and second users, thereby a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained for the proving operation.

20. A computer-readable storage medium which, when used by a computer for processing information on a transaction that is carried on between at least two users, causes the computer to perform the processes of:

creating digital signature data of a first user for transaction document data which contains information on the transaction between said first user and a second user, the digital signature data of the first user indicating approval for the information on the transaction;

transmitting the transaction document data and the digital signature data of said first user to a third party through a communication network;

receiving digital signature data of said second user for the transaction document data which has been verified with the transaction document data by the third party and digital signature data of the third party for data which contain at least one of the digital signature data of said first user and the digital signature data of said second user, from said third party through the network, the digital signature data of the second user indicating approval for the information on the transaction; and

storing said transaction document data, said digital signature data of said first user and the digital signature data of said second user as a guarantee of the transaction, and the digital signature data of the third party,

wherein a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

21. A computer-readable storage medium which, when used by a computer for processing information on a transaction that is carried on between at least two users, causes the computer to perform the processes of:

creating digital signature data of a first user for transaction document data which contains information on the transaction between said first user and a second user, the digital signature data of the first user indicating approval for the information on the transaction;

receiving digital signature data of said second user for the transaction document data, from said second user through a communication network, digital signature data of the second user indicating approval for the information on the transaction;

transmitting the digital signature data of said first user and the digital signature data of said second user to a third party through the network, and receiving digital signature data of the third party for data which contains at least one of the digital signature data of said first user and the digital signature data of said second user from the network; and

storing said transaction document data, said digital signature data of said first user and said digital signature data of said second user as a guarantee of the transaction and the digital signature data of the third party,

wherein a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

22. A transaction proof method for processing information on a transaction which is carried on between at least two users, comprising:

creating transaction document data which contains information on the transaction between a first user and a second user;

creating digital signature data of said first user and digital signature data of said second user for the transaction document data, the digital signature data of the first user and the digital signature data of the second user indicating approval for the information on the transaction;

transmitting the digital signature data of said first user and the digital signature data of said second user to a third party through a communication network, and receiving digital signature data of the third party for data which contains at least one if the digital signature data of said first user and the digital signature data of said second user from the network;

verifying said digital signature data of said first user and said digital signature data of said second user;

preserving said transaction document data, said digital signature data of said first user, said digital signature data of said second user and the digital signature data of the third party; and

proving in response to a request that the transaction was carried out between the first and second users, by using the preserved data,

wherein a combination of the transaction document data, the digital signature data of the first user, the digital signature data of the second user, and the digital signature data of the third party is retained by the first and second users and the third party.

23. A transaction proof apparatus comprising:

a communication device receiving a private-key encrypted transaction document from a first user and a private-key encrypted transaction document from a second user;

a processing device decrypting both the encrypted transaction document from the first user and the encrypted transaction document from the second user, and verifying that both decrypted documents are identical; and

a storage device, on condition that both decrypted documents are identical, storing data proving that both users agreed on the transaction, said data being stored for future retrieval to a requestor.

24. A process for proving a transaction to a requestor comprising:

encrypting a first transaction document with a first user private key;

sending the encrypted first transaction document to a proving apparatus;

encrypting a second transaction document with a second user private key;

sending the encrypted second transaction document to the proving apparatus;

decrypting the first encrypted transaction document and the second encrypted transaction document by the proving apparatus;

comparing the first decrypted transaction document and the second decrypted transaction document, and if identical then storing transaction data verifying the transaction for future retrieval; and

delivering the transaction data to the requestor.

25. A transaction proof apparatus for processing information on a transaction which is carried on between at least two users, comprising:

a communication device, connected to a communication network, receiving from the network digital signature data of a first user in conjunction with a first transaction document data which contains information on the transaction between the first and second users, and receiving from the network digital signature data from a second user in conjunction with a second transaction document data which contains information on the transaction between the first and second users, the digital signature data of the first user and the digital signature data of the second user indicating approval for the information on the transaction;

a processing device verifying the digital signature data of said first user and the digital signature data of said second user;

a storage device storing therein said digital signature data of said first user and said digital signature data of said second user in proof of the transaction if the received first transaction document data is identical to the received second transaction document data; and

a proving device proving in response to a request that the transaction was carried out between the first and second users by using data stored in the storage device.