Certificate management in ad hoc networks

Various types of certificates are basic tools of modern cryptography and network security. They are used in various protocols, in the form of public key identity certificates, binding a key to its owner or in the form of attribute certificates, being a proof of rights and capabilities of their owner. Management of certificates (creation, distribution, verification, and revocation) is dependent on a certification infrastructure comprising various certification authorities, protocols, and policies. In this paper we consider usage and management of certificates in open, ad hoc networks. Ad hoc networks differ from fixed, wired networks in several important aspects, one of them being that access to the Internet is not always available. This significantly influences certificate management protocols since online access to various certificate system resources (CA certificates, CRL, etc) is not always available. We specify security requirements and constraints in such environments and outline potential solutions for adaptation of certificate management protocols to these new network environments.