DIGITAL SIGNATURE SOFTWARE USING EPHEMERAL PRIVATE KEY AND SYSTEM

• US 20060156013A1
• Filed: 08/08/2005
• Published: 07/13/2006
• Est. Priority Date: 01/07/2005
• Status: Abandoned Application

• Current Assignee: First Data Corporation (Fiserv Incorporated)
• Original Assignee: First Data Corporation (Fiserv Incorporated)
• Inventors: Beeson, Curtis Linn
• Application Number:
  US11/161,567
• Publication Number:
  US 20060156013A1
• Time in Patent Office: Days
• US Class Current: 713/180
• 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 9/3066 involving algebraic varieties, e.g. elliptic or hyper-elliptic curves
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

Facilitating communication using a digital signature includes: communicating software to a first party; receiving from the first party a public key of a public-private key pair generated using the software; and recording in a database the public key in association with information pertaining to the software. The key pair is generated by: receiving input data from a user (UID); generating the private key as a deterministic function of the UID; clearing the UID from the computer system; generating the public key as a deterministic function of the private key; clearing the private key from the computer system; and exporting the public key. The software generates a digital signature by again receiving the UID and regenerating the private key using the deterministic function and UID, after which, the private key and UID again are cleared.

Claims

1. An invention comprising a method for facilitating communication by a first party using a digital signature, the method comprising the steps of:

(a) communicating software to the first party, the software including computer-executable instructions for

(i) generating an asymmetric public-private key pair by,

(A) receiving input data into a computer system from a user,

(B) generating a first key as a deterministic function of said received input data of said step (i)(A),

(C) following said step (i)(B) of generating the first key, clearing from the computer system said received data of said step (i)(A) so that said received data is no longer available for generating the first key,

(D) generating within the computer system a second key as a deterministic function of said generated first key of said step (i)(B), said generated first key comprising a private key of the asymmetric public-private key pair and said generated second key comprising a public key of the asymmetric public-private key pair,

(E) following said step (i)(D) of generating the second key, clearing said generated first key of said step (i)(B) from the computer system so that said generated first key is no longer available within the computer system, and

(F) exporting said generated second key of said step (i)(D) from the computer system,

(b) receiving from the first party a public key of an asymmetric public-private key pair generated using the software communicated to the first party in step (a); and

(c) recording in a database said received public key of the first party in association with information pertaining to said communicated software of said step (a).

2. The invention of claim 1, wherein the software further includes computer-executable instructions for

(ii) performing the steps of,

(A) receiving input data into a computer system from a user,

(B) regenerating the first key using the deterministic function of said step (i)(B) and said received data of said step (ii)(A),

(C) following said step (ii)(B) of regenerating the first key, clearing from the computer system said received data of said step (ii)(A) so that said received data is no longer available for regenerating the first key,

(D) generating within the computer system a digital signature as a function of said regenerated first key of said step (ii)(B),

(E) following said step (ii)(D) of generating the digital signature, clearing said regenerated first key of said step (ii)(B) from the computer system so that said generated first key is no longer available within the computer system, and

(F) exporting said generated digital signature from the computer system.

3. The invention of claim 1, wherein the information recorded in said step (c) comprises information regarding the deterministic function used to generate the first key in said step (i)(B).

4. The invention of claim 1, wherein the information recorded in said step (c) comprises information regarding the deterministic function used to generate the second key in said step (i)(D).

5. The invention of claim 1, wherein the information recorded in said step (c) comprises information regarding when step (i)(C) of clearing said received data is performed.

6. The invention of claim 1, wherein the information recorded in said step (c) comprises information regarding when step (i)(E) of clearing said generated first key is performed.

7. The invention of claim 1, wherein the information recorded in said step (c) comprises the version of the software.

8. The invention of claim 1, wherein the software further includes computer-executable instructions for generating within the computer system a digital signature as a deterministic function of said generated first key of said step (i)(B) before said step (i)(E) of clearing the first key is performed.

9. The invention of claim 1, wherein the software further includes computer-executable instructions for generating within the computer system a digital signature as a function of said generated first key of said step (i)(B) before said step (i)(E) of clearing the first key is performed and before said generated second key is exported in step (i)(F).

10. The invention of claim 9, wherein said generated digital signature of said step (a)(i) is exported with the second key in step (i)(F).

11. The invention of claim 1, wherein said step (a) of communicating the software comprises communicating the software to the first party over the Internet.

12. The invention of claim 11, wherein the software is downloaded from a website.

13. The invention of claim 1, wherein said step (a) is performed by a second party, and wherein said communicated software of said step (a) further includes computer-executable instructions for exporting information identifying said communicated software to the second party.

14. The invention of claim 13, wherein the identifying information includes a hash value of the software.

15. The invention of claim 13, wherein the identifying information is digitally signed using said communicated software.

16. The invention of claim 13, wherein the information identifying said communicated software to the second party is exported with the second key of said step (i)(F) for communicating to the second party.

17. The invention of claim 16, wherein the second party performs said step (c) of recording the received public key in association with the information, and wherein said recorded information pertains to the software identified to the second party by said identifying information.

18. The invention of claim 2, wherein the information recorded in said step (c) comprises information regarding when step (ii)(C) of clearing said received data is performed.

19. The invention of claim 2, wherein the information recorded in said step (c) comprises information regarding when step (ii)(E) of clearing said regenerated first key is performed.

20. The invention of claim 2, wherein the software further includes computer-executable instructions for receiving an electronic message, and wherein the digital signature is generated in said step (ii)(D) for said received electronic message.

21. The invention of claim 2, wherein the function of said step (ii)(D) of generating the digital signature further is a function of whether a digital signature has yet been generated using said regenerated first key of said step (ii)(B).

22. The invention of claim 2, wherein the software further includes computer-executable instructions for repeating said step (ii)(D) of generating a digital signature using said regenerated first key to thereby generate additional digital signatures.

23. The invention of claim 2, wherein said step (ii)(C) of clearing said received data is performed prior to said step (ii)(D) of generating a digital signature.

24. The invention of claim 2, wherein said steps (i) and (ii) of the software each are executed in a personal digital assistant (PDA).

25. The invention of claim 2, wherein said steps (i) and (ii) of the software each are executed in a telephonic device.

26. The invention of claim 2, wherein the information recorded in said step (c) comprises information regarding the function used to generate the digital signature in said step (ii)(D).

27. The invention of claim 26, wherein the software communicated in said step (a) utilizes elliptical curve cryptography in said step (ii)(D) of generating the digital signature, and wherein the information regarding the function of said step (ii)(D) comprises an identification of domain parameters used in the elliptical curve cryptography.

28. The invention of claim 26, wherein the software communicated in said step (a) utilizes elliptical curve cryptography in said step (ii)(D) of generating the digital signature, and wherein the information regarding the function of said step (ii)(D) comprises an identification of a generating point used in the elliptical curve cryptography.

29. The invention of claim 2, wherein the software further includes computer-executable instructions for maintaining an indicator of whether, following the receipt of the input data in said step (ii)(A), a digital signature has been generated in step (ii)(D) using said regenerated first key of said step (ii)(B).

30. The invention of claim 29, wherein the deterministic function of said step (ii)(D) of generating the digital signature further is a function of said maintained indicator.