Method of establishing secure communications in a digital network using pseudonymic digital identifiers

• US 20030115457A1
• Filed: 12/18/2002
• Published: 06/19/2003
• Est. Priority Date: 12/19/2001
• Status: Active Grant

• Current Assignee: IQVIA, Inc. (IQVIA Holdings, Inc.)
• Original Assignee: Diversinet Corporation
• Inventors: Ansell, Stephen M., Crerar, Michael C., Wildish, Michael Andrew
• Granted Patent: US 7,103,774 B2
• Time in Patent Office: Days
• US Class Current: 713/157
• CPC Class Codes: H04L 2209/42 Anonymization, e.g. involving pseudonyms
• CPC Class Codes: H04L 9/3265 using certificate chains, trees or paths; Hierarchical trust model

Abstract

A system and method of relating a public key to a compact identification string in a digital certificate to enable an entity to construct a certificate chain from a root certificate authority to an end-entity efficiently and further allow a certificate holder to store only its identifier, thus providing privacy protection, and present this in place of a digital certificate for authentication rather than storing and presenting its certificate or a chain of certificates representing the certificate path up to the root certificate authority. In a preferred embodiment, the certificate authority generates unique identifier for each certificate consisting its pseudonym concatenated with the pseudonyms of other sub-certificate authorities in the certificate chain between it and the certificate holder, concatenated with certificate holder'"'"'s pseudonym. The pseudonyms are generated by the entity known by the pseudonym or the entity certifying a binding between the pseudonym and the entity'"'"'s public key.

Claims

1. A method of establishing a secure communication in a digital communications network having a hierarchical arrangement of certificate servers, comprising the steps of:

generating a first private/public key pair in a root certificate server;

issuing a digital certificate for a public key portion of said first private/public key pair signed by said root certificate server and identified by a digital identifier associated with said root certificate server;

generating additional private/public key pairs in subordinate entities and associating public key portions of said additional private/public key pairs with pseudonymic digital identifiers associated with said respective subordinate entities; and

,

issuing additional digital certificates binding said pseudonymic digital identifiers of said subordinate entities to the public key portion of their respective private/public key pairs from certificate servers that are in parental relationship to said subordinate entities, said additional digital certificates having a digital certificate identifier containing the pseudonymic digital identifier of the certified subordinate entity and the identifier of said certificate server issuing the additional digital certificate.

2. A method as claimed in claim 1, wherein the subordinate entities requesting digital certificates are assigned pseudonymic digital identifiers by the root server.

3. A method as claimed in claim 1, wherein the subordinate entities requesting digital certificates generate their own pseudonymic digital identifiers.

4. A method as claimed in claim 1, wherein said pseudonymic digital identifiers are random strings.

5. A method as claimed in claim 1, wherein said pseudonymic digital identifiers are selected by a third party.

6. A method as claimed in claim 1, wherein said hierarchical arrangement of certificate servers is in the form of at least one chain of certificate servers, and lower level certificate servers issue digital certificates with identifiers containing all the identifiers of higher level certificate servers in the hierarchy.

7. A method as claimed in claim 1, wherein said additional digital certificates have a digital certificate identifier that is a concatenation of the pseudonymic digital identifier of the certified subordinate entity and the identifier of said certificate server issuing the additional digital certificate.

8. A method as claimed in claim 1, wherein said subordinate entities comprise said subordinate certificate servers.

9. A method as claimed in claim 1, wherein said subordinate entities also include end users.

10. A method as claimed in claim 9, wherein said root server issues digital certificates for at least some of said end users.

11. A method as claimed in claim 9, wherein certificate servers that are subordinate to said root server issue digital certificates to at least some of said end users.

12. A method of establishing a secure communication in a digital communications network having a hierarchical arrangement of a certificate servers wherein higher level certificate servers issue digital certificates for certificate servers lower in the hierarchy, comprising the steps of:

generating a first private/public key pair in a root certificate server;

issuing a digital certificate for a public key portion of said first private/public key pair signed by said root certificate server and identified by a digital identifier associated with said root certificate server;

generating additional private/public key pairs in subordinate certificate servers and associating public key portions of said additional private/public key pairs with pseudonymic digital identifiers associated with said respective subordinate certificate servers; and

,

issuing additional digital certificates binding said pseudonymic digital identifiers of said subordinate certificate servers to the public key portion of their respective private/public key pairs from certificate servers that are in parental relationship to said subordinate entities, said additional digital certificates having a digital certificate identifier containing the pseudonymic digital identifier of the certified subordinate entity and the digital identifier the or each higher level certificate server in said hierarchical arrangement up to the root certificate server.

13. A method as claimed in claim 12, wherein said digital certificate identifiers for said additional digital certificates comprise a concatenation of the digital identifiers for the or each higher level certificate server up to the root server.

14. A digital communications network capable of providing secure communication, comprising:

a root certificate server associated with a private and public key and a digital certificate signed by said root certificate server certifying the public key thereof, said root certificate server having a memory for storing said digital certificate, and said memory including a register portion for storing a digital identifier associated with said root certificate server;

a plurality of subordinate entities associated with respective pseudonymic digital identifiers and comprising subordinate certificate servers and end users in a hierarchical arrangement with said root certificate server, said subordinate certificate servers issuing digital certificates to lower level entities in said hierarchical arrangement to bind public keys of said lower level entities to their respective pseudonymic digital identifiers; and

,

said subordinate certificate servers having memories for storing an identifier for the issued digital certificates, said memories including a first register portion for storing the pseudonymic digital identifier of the issuing certificate server and at least one additional register portion for storing the digital identifier of the or each higher level certificate server in said hierarchical arrangement.

15. A digital communications network as claimed in claim 14, wherein said register portions of said memories in said subordinate certificate servers correspond to fields, each containing a digital identifier.

16. A digital communications network as claimed in claim 15, wherein said fields are arranged to concatenate the digital identifiers of each certificate server in said hierarchical arrangement.

17. A digital communications network as claimed in claim 14 wherein said subordinate entities comprises random number generators for generating said pseudonymic digital identifiers.