Generating Correlated Digital Certificates: Framework and Applications

Bolstering public key authentication of networking entities, digital certificates are an entrenched part of Internet security. A digital certificate is an electronic document signed by a certificate authority (CA), vouching that the identified subject owns the declared public key (and the corresponding private key). In general, CAs are also responsible for certificate revocation as well as reissue, and certificates by nature are considered independent of each other. In this paper, we address the problem of certificate management and propose a flexible framework to create correlated certificates. We then apply it to implement the so-called multi-certificate public key infrastructure, which supports user self services, such as certificates' spontaneous substitution as well as self-reissue after self-revocation. To the best of our knowledge, this is the first scheme for certificate users to achieve self-reissue. Another application of the proposed framework is the so-called anonymous digital certificate, which still binds a user's identity to her public key, but in an anonymous yet user-controllable manner. That is, a user can reveal her identity-key binding only to her specified communication peers, while remaining anonymous to the general public, achieving privacy as these certificates are generally unlinkable.