Risk management for public key management infrastructure using digital certificates

• US 6,324,645 B1
• Filed: 08/11/1998
• Issued: 11/27/2001
• Est. Priority Date: 08/11/1998
• Status: Expired due to Term

• Current Assignee: DigiCert Incorporated
• Original Assignee: VeriSign, Inc.
• Inventors: Williams, Peter, Lin, Judy, Andrews, Richard F
• Primary Examiner(s): Chung, Phung M.
• Assistant Examiner(s): JACK, TODD M
• Application Number:
  US09/132,289
• Time in Patent Office: 1,204 Days
• Field of Search: 713/176, 713/175, 713/170, 713/169, 713/168, 713/157, 713/156, 380/30, 380/282, 380/285
• US Class Current: 713/157
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/006 involving public key infrastructure [PKI] trust models network architecture or network communication protocol for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823

Abstract

A public key management infrastructure (104) is shared by at least two users (102). A method (300) for managing risk arising from a user'"'"'s use of the shared public key management infrastructure (104) includes the following steps. The user (102) is associated (301) with a digital certificate (200) which is issued and digitally signed by a certification authority (CA). The digital certificate (200) represents that the user (102) is bound to a public key (210) corresponding to a private key held by the user (102); the public key (210) and the private key form a key pair for use in public-key cryptography. The digital certificate (200) further includes an access label (216), which may identify the domain (105) within the public key management infrastructure (104) which the user (102) is authorized to access and/or the privileges which the user (102) is authorized to exercise. The user'"'"'s identity and the validity of the digital certificate (200) are established (303,305). The access label (216) is read (304) from the user'"'"'s digital certificate (200), and the user'"'"'s use of the public key management infrastructure (104) is controlled (306) based upon the access label (216).

Claims

1. In a system including a public key management infrastructure shared by at least two groups of users, wherein the public key management infrastructure includes a database of digital certificates issued to the users, a method for managing risk arising from a user'"'"'s use of the public key management infrastructure, the method comprising:

dividing the database into domains, each domain including digital certificates issued to users in one of the groups;

receiving a digital certificate for a user, wherein the digital certificate is issued by a CA to the user, the digital certificate represents that the user is bound to a public key corresponding to a private key held by the user, the public key and the private key form a key pair for use in public-key cryptography, the digital certificate includes a domain identifier, and the digital certificate is digitally signed by the CA;

establishing a validity of the digital certificate;

establishing the user'"'"'s identity;

reading the domain identifier from the user'"'"'s digital certificate; and

permitting the user to access digital certificates included in the domain identified by the domain identifier.

2. The method of claim 1 wherein:

the database includes records, each record including information pertaining to a digital certificate;

each domain includes records for digital certificates in the domain;

each record includes a domain identifier for identifying which domain includes the record; and

the step of permitting the user to access the digital certificates includes precluding the user from accessing a record when the domain identifier in the record does not match the domain identifier contained in the user'"'"'s digital certificate.

3. The method of claim 1 wherein:

the database includes records, each record including information pertaining to a digital certificate;

each domain includes records for digital certificates in the domain;

each record includes a domain identifier for identifying which domain includes the record; and

the step of permitting the user to access the digital certificates includes permitting the user to access a record when the domain identifier in the record matches the domain identifier contained in the user'"'"'s digital certificate.

4. The method of claim 1 wherein:

the database includes records, each record including information pertaining to a digital certificate;

each domain includes records for digital certificates in the domain;

each record includes a domain identifier for identifying which domain includes the record;

the step of receiving a digital certificate for a user comprises receiving a digital certificate for a PKI administrator; and

the step of permitting the user to access the digital certificates includes permitting the PKI administrator to change a record when the domain identifier in the record matches the domain identifier contained in the PKI administrator'"'"'s digital certificate.

5. The method of claim 4 wherein:

the PKI administrator'"'"'s digital certificate further includes privileges information; and

the step of permitting the user to access the digital certificates includes permitting the PKI administrator to change a record according to the privileges information.

6. The method of claim 4 further comprising the step of:

generating a record of changes made by the PKI administrator.

7. A computer readable medium for managing risk arising from a user'"'"'s use of a public key management infrastructure, wherein the public key management infrastructure is shared by at least two groups of users and includes a database of digital certificates issued to users, the computer readable medium storing:

a digital certificate issued by a CA to a user, wherein the digital certificate represents that the user is bound to a public key corresponding to a private key held by the user, the public key and the private key form a key pair for use in public-key cryptography, the digital certificate is digitally signed by the CA, and the digital certificate includes;

user information pertaining to the user, and

a domain identifier which permits the user to access digital certificates included in the domain identified by the domain identifier, wherein the domain includes digital certificates for the user'"'"'s group.

8. The computer readable medium of claim 7 wherein:

the domain identifier additionally identifies the user'"'"'s group.

9. The computer readable medium of claim 7 wherein:

the domain identifier includes information that has been one-way hashed.

10. The computer readable medium of claim 7 wherein:

the digital certificate complies with the X.509 format; and

the domain identifier is contained in an X.509 extension.

11. A method for managing risk arising from a user'"'"'s use of a public key management infrastructure, wherein the public key management infrastructure is shared by at least two groups of users and includes a database of digital certificates issued to users, the method comprising:

receiving information pertaining to a user;

including in a digital certificate user information pertaining to the user, wherein the digital certificate is issued by a CA, the digital certificate represents that the user is bound to a public key corresponding to a private key held by the user, the public key and the private key form a key pair for use in public-key cryptography, and the digital certificate is digitally signed by the CA;

determining a domain identifier appropriate for the user, wherein the domain identifier permits the user to access digital certificates included in the domain identified by the domain identifier, and the domain includes digital certificates for the user'"'"'s group; and

including in the digital certificate the domain identifier.

12. The method of claim 11 wherein:

the digital certificate complies with the X.509 format; and

the step of including in the digital certificate the domain identifier comprises including the domain identifier in an X.509 extension.

13. The method of claim 11 wherein:

the step of receiving information pertaining to a user comprises receiving information pertaining to the user'"'"'s group; and

the step of determining a domain identifier appropriate for the user comprises determining the domain identifier for the user'"'"'s group.

14. The method of claim 13 wherein:

the step of receiving information pertaining to the user'"'"'s group comprises receiving a name of the user'"'"'s group; and

the step of including in the digital certificate a domain identifier comprises;

producing a one-way hash of the name of the user'"'"'s group, and

including the one-way hash in the digital certificate.

15. A system comprising:

a public key management infrastructure shared by at least two groups of users and including a database of digital certificates issued to users;

a security engine coupled to the public key management infrastructure for managing risk arising from shared use of the public key management infrastructure; and

a digital certificate accessible by the security engine, wherein the digital certificate is issued by a CA to the user, the digital certificate represents that the user is bound to a public key corresponding to a private key held by the user, the public key and the private key form a key pair for use in public-key cryptography, the digital certificate includes a domain identifier, and the digital certificate is digitally signed by the CA;

wherein the security engine establishes the user'"'"'s identity, validates the user'"'"'s digital certificate, and permits the user to access digital certificates included in the domain identified by the domain identifier, such domain including digital certificates for the user'"'"'s group.

16. The system of claim 15 wherein:

the database includes records, each record containing information pertaining to a digital certificate;

each domain includes records for digital certificates in the domain;

each record includes a domain identifier for identifying which domain includes the record; and

the security engine permits the user to access a record when the domain identifier in the user'"'"'s digital certificate matches the domain identifier in the record.