Distributed split-key cryptosystem and applications

• US 6,026,163 A
• Filed: 12/12/1996
• Issued: 02/15/2000
• Est. Priority Date: 12/13/1995
• Status: Expired due to Term

• Current Assignee: Silvio Micali
• Original Assignee: Silvio Micali
• Inventors: Micali, Silvio
• Primary Examiner(s): Swann, Tod R.
• Assistant Examiner(s): Callahan, Paul E.
• Application Number:
  US08/766,448
• Time in Patent Office: 1,160 Days
• Field of Search: 380/4, 380/21, 380/25, 380/28, 380/29, 380/30, 380/43, 380/44, 380/45, 380/46, 380/49, 380/59, 705/1, 705/37, 705/74, 705/77, 705/78, 705/80, 713/168, 713/171
• US Class Current: 705/80
• CPC Class Codes: G06Q 20/085 involving remote charge determination or related payment systems
• CPC Class Codes: G06Q 20/0855 involving a third party
• CPC Class Codes: G06Q 20/382 insuring higher security of transaction
• CPC Class Codes: G06Q 20/3829 involving key management
• CPC Class Codes: G06Q 20/383 Anonymous user system
• CPC Class Codes: G06Q 50/188 Electronic negotiation
• CPC Class Codes: H04L 2209/466 Electronic auction
• CPC Class Codes: H04L 9/3013 involving the discrete logarithm problem, e.g. ElGamal or Diffie-Hellman systems

Abstract

A distributed split-key cryptosystem and application in a public-key setting wherein each of a plurality of trustees independently selects his own secret-public key pair. The trustees combine their public encryption keys into a single public encryption key. Using this combined public key for an electronic auction and other secure transactions.

Claims

1. A method for an electronic auction with encrypted bids, comprising:

having each of a plurality of trustees generate an individual public key with a corresponding individual secret key;

combining the individual public keys of the plurality of trustees into a combined public key;

encrypting a bid of a user with the combined public key;

reconstructing a combined secret key corresponding to the combined public key from the individual secret keys of the plurality of trustees; and

using the combined secret key to decrypt the user'"'"'s bid.

2. A method according to claim 1, wherein the bid of a user is encrypted together with an indication of an identity of the user.

3. A method according to claim 1, wherein the bid of the user includes an indication of an identity of the user.

4. A method as in claim 1, wherein the bid of the user in encrypted so as to avoid that the bid of the user is copied by another user.