Method for the application of implicit signature schemes

• US 8,522,012 B2
• Filed: 10/31/2011
• Issued: 08/27/2013
• Est. Priority Date: 06/09/2000
• Status: Expired due to Fees

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Certicom Corporation (Blackberry Limited)
• Inventors: Vanstone, Scott A.
• Primary Examiner(s): Schwartz, Darren B
• Assistant Examiner(s): TRUVAN, LEYNNA THANH
• Application Number:
  US13/285,749
• Publication Number:
  US 20120102318A1
• Time in Patent Office: 666 Days
• Field of Search: None
• US Class Current: 713/156
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/64 Self-signed certificates
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]

Abstract

A method of certifying a correspondent in a data communication system by a certifying authority. The certifying authority includes a cryptographic unit. The method includes generating a random number and implicit certificate components based on the random number using the cryptographic unit. The implicit certificate components have a first component and a second component. The method also includes providing the implicit certificate components for use in the data communication system and providing a public key of the certifying authority for use in derivation of a public key of the correspondent from the first component. The certifying authority recertifies the correspondent by providing implicit certificate components using a changed value for the random number.

Claims

1. A method of a certifying a correspondent in a data communication system by a certifying authority, said certifying authority including a cryptographic unit, said method comprising:

said certifying authority generating a random number c_A using said cryptographic unit;

said certifying authority generating implicit certificate components based on said random number c_A using said cryptographic unit, said implicit certificate components having a first component γ

_A and a second component s_A;

said certifying authority providing said implicit certificate components for use in said data communication system; and

said certifying authority providing a public key of said certifying authority for use in derivation of a public key of said correspondent from said first component γ

_A;

wherein said certifying authority recertifies said correspondent by providing implicit certificate components using a changed value for said random number.

2. The method of claim 1, wherein said second component s_A is generated using said first component γ

_A and a private key of said certifying authority.

3. The method of claim 1, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=h(γ

_A∥

ID_A∥

cP)c+c_A (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

4. The method of claim 1, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=h(γ

_A∥

ID_A∥

cP)c_A+c (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

5. The method of claim 1, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=c_A±

ch(ID_A∥

γ

_A) (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

6. The method of claim 1, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=c_Ah(ID_A∥

γ

_A)±

c (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

7. The method of claim 1 further comprising recertifying one or more correspondents whose certificates have not been revoked.

8. The method of claim 7, wherein said recertifying utilizes information previously received from said correspondent.

9. The method of claim 1, wherein said recertifying occurs with a certification period.

10. A non-transitory computer-readable medium having stored thereon computer-executable instructions for certifying a correspondent in a data communication system by a certifying authority, said computer-executable instructions comprising instructions for:

generating a random number c_A;

generating implicit certificate components based on said random number c_A, said implicit certificate components having a first component γ

_A and a second component s_A;

providing said implicit certificate components for use in said data communication system; and

providing a public key of said certifying authority for use in derivation of a public key of said correspondent from said first component γ

_A;

wherein said computer-executable instructions further comprise instructions for recertifying said correspondent by providing implicit certificate components using a changed value for said random number.

11. The non-transitory computer-readable medium of claim 10, wherein said second component s_A is generated using said first component γ

_A and a private key of said certifying authority.

12. The non-transitory computer-readable medium of claim 10, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=h(γ

_A∥

ID_A∥

cP)c+C_A (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

13. The non-transitory computer-readable medium of claim 10, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=h(γ

_A∥

ID_A∥

cP)c_A+c (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

14. The non-transitory computer-readable medium of claim 10, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=c_A±

ch(ID_A∥

γ

_A) (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

15. The non-transitory computer-readable medium of claim 10, wherein

said first component γ

_A=aP+c_AP, wherein aP is provided to said certifying authority by said correspondent and P is a point on a curve; and

said second component s_A=c_Ah(ID_A∥

γ

_A)±

c (mod n), wherein c is a private key of said certifying authority, n is a large prime number, ID_A is an identifier of said correspondent and includes at least one distinguishing feature of said correspondent; and

h indicates a secure hash function.

16. The non-transitory computer-readable medium of claim 10, said computer-executable instructions further comprising instructions for recertifying one or more correspondents whose certificates have not been revoked.

17. The non-transitory computer-readable medium of claim 10, wherein said recertifying utilizes information previously received from said correspondent.

18. The non-transitory computer-readable medium of claim 10, wherein said recertifying occurs with a certification period.

19. A certifying authority for certifying a correspondent in a data communication system, said certifying authority including a cryptographic unit for:

generating a random number c_A;

generating implicit certificate components based on said random number c_A, said implicit certificate components having a first component γ

_A and a second component s_A;

providing said implicit certificate components for use in said data communication system;

providing a public key of said certifying authority for use in derivation of a public key of said correspondent from said first component γ

_A;

wherein said certifying authority further includes said cryptographic unit for recertifying said correspondent by providing implicit certificate components using a changed value for said random number.

20. The certifying authority of claim 19, wherein said second component s_A is generated using said first component γ

_A and a private key of said certifying authority.