Secure auction systems

• US 6,055,518 A
• Filed: 11/12/1996
• Issued: 04/25/2000
• Est. Priority Date: 02/01/1996
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Franklin, Matthew K., Reiter, Michael K.
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): CAUDLE, PENNY L
• Application Number:
  US08/745,717
• Time in Patent Office: 1,260 Days
• Field of Search: 705/37, 705/64, 705/67, 380/4, 380/21, 380/23, 380/25, 380/30, 380/33
• US Class Current: 705/37
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/382 insuring higher security of transaction
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions
• CPC Class Codes: G06Q 40/04 Trading; Exchange, e.g. stocks, commodities, derivatives or currency exchange
• CPC Class Codes: H04L 2209/42 Anonymization, e.g. involving pseudonyms
• CPC Class Codes: H04L 2209/466 Electronic auction
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

The apparatus and method of the present invention provide secure auction service for use in a network having servers and bidding terminals. The auction service makes transactions among servers and bidding terminals subject to a distributed protocol. The distributed protocol distributes submitted bids among the multiple servers, closes a bidding period, verifies validity of monetary value of each submitted bid by utilizing said distributed protocol and determines a winning bidder.

Claims

1. A method for making transactions in a secure auction service network having a plurality of servers connected to a plurality of bidding terminals, said transaction being subject to a distributed protocol, said method comprising:

submitting from said bidding terminals monetary bids and distributing each of said monetary bids among said servers during a bidding period subject to a distributed protocol;

closing said bidding period;

verifying at said servers validity of monetary value of each of said monetary bids by utilizing said distributed protocol;

collectively determining a winning bidding terminal among said plurality of bidding terminals;

wherein said distributed protocol requires that said monetary bids be encoded using public information and private keys for distribution to said servers;

wherein said distributed protocol requires that said encrypted monetary bids be individually distributed in shares among said servers; and

wherein said distributed protocol requires that said servers validate said monetary bids by decrypting said encrypted monetary bids using said private keys and evaluating the consistency with said public information.

2. The method as defined in claim 1, further comprising the step of determining a set of said monetary bids that pass said verifying step prior to said determining step.

3. The method as defined in claim 1, wherein said determining step follows a public auction service rule.

4. The method as defined in claim 1, wherein said bid is made with a digital coin, said digital coin is characterized by <

v_$, σ

_bank (v_$), w_$ >

where v_$ is a description, σ

_bank (v_$) is a digital signature and w_$ is auxiliary information.

5. The method as defined in claim 4, wherein said description v_$ and said auxiliary information w_$ are shared among said servers with a standard (t,n) threshold secret sharing scheme and wherein said digital signature σ

_bank (v_$) is shared among said servers with a verifiable signature sharing VΣ

S scheme.

6. The method as defined in claim 5, wherein said verifying step comprises:

reconstructing said description v_$ and said auxiliary w_$ ; and

performing said verifiable signature sharing VΣ

S scheme to determine said validity of each of said monetary bids.

7. The method as defined in claim 6, wherein said performing step comprises the step of determining if said servers collectively possess said digital signature σ

_bank (v_$).

8. The method as defined in claim 5, further comprising the steps of:

reconstructing said digital signature σ

_bank (v_$) of said winning bid via said VΣ

S scheme; and

depositing said digital coin.

9. The method as defined in claim 5, further comprising the step of accompanying said description v_$ includes identity of said bidding terminal in the form of a pseudonym.

10. The method as defined in claim 5, further comprising the steps of:

encoding identity of said bidding terminal into a pseudonym prior to said submitting step; and

decoding said pseudonym into identity of said bidding terminal of said winning bid after said determining step.

11. A method for making transactions in a service network having a plurality of servers and a plurality of remote stations connected to said servers, said transactions being subject to distributed protocols, said method comprising:

submitting offers from said remote stations to said servers by;

i. encoding each of said offers into a plurality of shares utilizing said distributed protocols;

ii. individually distributing said shares of each of said offers among said servers;

reconstructing at said servers portions of said offers by utilizing said distributed protocol;

verifying collectively among said servers the validity of said portions of said offers;

accepting collectively among said servers at least one of said verified offers based on a predetermined rule;

wherein said distributing step includes the steps of sending public information to said servers and sending private keys to appropriate servers; and

wherein said verifying step includes the step of evaluating consistency of said decrypted share with said public information.

12. The method as defined in claim 11 further comprising reconstructing said at least one accepted offer.

13. The method as defined in claim 11, wherein said verifying step is based on a verifiable signature sharing VΣ

S scheme.

14. A secure auction system for making transactions subject to distributed protocol comprising:

a plurality of bidding terminals configured for submitting monetary bids and individually distributing said monetary bids among a plurality of servers connected to said bidding terminals during a bidding period;

said servers configured for closing said bidding period, for collectively verifying a validity of monetary value of each of said monetary bids by utilizing said distributed protocol and for collectively determining a winning bidding terminal;

wherein said bidding terminals encode said monetary bids using public information and private keys; and

wherein said servers verify said monetary value of each of said monetary bids by decrypting said monetary bids with said private keys and evaluating the consistency with said public information.

15. The secure auction system as defined in claim 14, wherein said servers are configured for agreeing on a set of said verified monetary bids prior to determining said winning bidding terminal.

16. The secure auction system as defined in claim 14, wherein said servers are configured for reconstructing said monetary bid from said winning bidding terminal.

17. The secure auction system as defined in claim 14, wherein said monetary bids includes identity of said bidding terminal.