PKI Interoperability Models (February 2005)

1. Introduction

PKI is still considered the problem teenager of e-commerce. Its applications have been limited to small closed groups, defying the often unreasonable hype suggesting promising that PKI will revolutionise all forms of electronic transactions. But with patience, the demand will grow for more and more PKI systems to interoperate. The full potential of electronic signatures may only be realised if the large organisations that issue digital certificates, Certification Authorities (CAs), are interoperable.

PKI interoperability models are now the subject of discussion, research and pilot testing in international and regional forums. This article explains and assesses the leading PKI interoperability models that have emerged and the early attempts being made around the world to use them.