Data card verification system

• US 7,472,276 B2
• Filed: 07/01/2002
• Issued: 12/30/2008
• Est. Priority Date: 02/03/1997
• Status: Expired due to Term

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Certicom Corporation (Blackberry Limited)
• Inventors: Vanstone, Scott A
• Primary Examiner(s): Moise; Emmanuel L
• Assistant Examiner(s): CALLAHAN, PAUL E
• Application Number:
  US10/185,042
• Publication Number:
  US 20020174339A1
• Time in Patent Office: 2,374 Days
• Field of Search: 380/278, 380281-285, 380/28, 380/30, 713/171, 713/176, 713/175
• US Class Current: 713/175
• 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 20/3674 involving authentication
• CPC Class Codes: G06Q 20/3825 Use of electronic signatures
• CPC Class Codes: G06Q 20/401 Transaction verification
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G06Q 2220/00 Business processing using cryptography postage metering system using cryptography G06Q2250/05
• 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: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3066 involving algebraic varieties, e.g. elliptic or hyper-elliptic curves
• CPC Class Codes: H04L 9/3249 using RSA or related signature schemes, e.g. Rabin scheme
• CPC Class Codes: H04L 9/3252 using DSA or related signature schemes, e.g. elliptic based signatures, ElGamal or Schnorr schemes

Abstract

A method of verifying a pair of correspondents in electronic transaction, the correspondents each including first and second signature schemes and wherein the first signature scheme is computationally more difficult in signing than verifying and the second signature scheme is computationally more difficult in verifying than signing. The method comprises the step of the first correspondent signing information according to the first signature scheme and transmitting the first signature to the second correspondent, the second correspondent verifying the first signature received from the first correspondent, wherein the verification is performed according to the first signature scheme. The second correspondent then signs information according to the second signature scheme and transmits the second signature to the first correspondent, the first correspondent verifies the second signature received from the second correspondent, wherein the verification is performed according to the second signature algorithm; the transaction is rejected if either verification fails. The method thereby allows one of the correspondents to participate with relatively little computing power while maintaining security of the transaction.

Claims

1. A method of generating a certificate in a public key cryptosystem comprising the steps of:

a) obtaining from a correspondent, a first set of data representing public information of said correspondent associated with a first signature scheme, said first signature scheme utilizing an elliptic curve cryptosystem, said public information being related to a private key generated by said correspondent;

b) signing a second set of data according to a second signature scheme that is different than said first signature scheme to obtain a signature; and

c) combining said first set of data and said signature to generate said certificate.

2. A method according to claim 1 wherein said second set of data is signed utilizing an RSA cryptosystem.

3. A method according to claim 2 wherein said second set of data comprises said public information.

4. A method according to claim 3 wherein said certificate includes an ID of said correspondent and said step of signing said public information relates said ID to said public information including said public key.

5. A method according to claim 3, wherein said public information comprises a public key for use in said elliptic curve cryptosystem.

6. A method according to claim 1, wherein said public information comprises a public key for use in said elliptic curve cryptosystem.

7. A method according to claim 1, wherein said second signature scheme is computationally more difficult in signing than verifying, while said first signature scheme is computationally more difficult in verifying than signing, thereby allowing said correspondent to participate with relatively little computing power while maintaining security of a transaction.

8. A method according to claim 1, wherein said second set of data is signed by a certificate authority.

9. A computer readable medium comprising computer executable instructions for generating certificate including instructions for:

a) obtaining from a correspondent, a first set of data representing public information of said correspondent associated with a first signature scheme, said first signature scheme utilizing an elliptic curve cryptosystem, said public information being related to a private key generated by said correspondent;

b) signing a second set of data according to said second signature scheme that is different than said first signature scheme to obtain a signature; and

c) combining said first set of data and said signature to generate said certificate.

10. A computer readable medium according to claim 9 wherein said second set of data is signed utilizing an RSA cryptosystem.

11. A computer readable medium according to claim 10 wherein said second set of data comprises said public information.

12. A computer readable medium according to claim 11, wherein said public information comprises a public key for use in said elliptic curve cryptosystem.

13. A computer readable medium according to claim 11 wherein said certificate includes an ID of said correspondent and said step of signing said public information relates said ID to said public information including said public key.

14. A computer readable medium according to claim 9, wherein said public information comprises a public key for use in said elliptic curve cryptosystem.

15. A computer readable medium according to claim 9, wherein said second signature scheme is computationally more difficult in signing than verifying, while said first signature scheme is computationally more difficult in verifying than signing, thereby allowing said correspondent to participate with relatively little computing power while maintaining security of a transaction.

16. A computer readable medium according to claim 9, wherein said second set of data is signed by a certificate authority.