PKI and digital certification infrastructure

Secure VPN technology is only possible with the use of appropriate security systems such as encryption, digital signatures, digital certificates, public/private key pairs, non-repudiation, and time-stamping. A PKI comprises a system of certificates, certificate authorities, subjects, relying partners, registration authorities, and key repositories that provide for safe and reliable communications. This paper discusses these key technologies focusing particularly on recent standardisation as well as looking at some of the challenges pending its widespread operation in the industry.