Underpinning the technicality of a public key infrastructure (PKI) is a system of rules and policies that dictate how digital certificates will be issued and used. Each different type of digital certificate has different documents attached to it.

The effectiveness and reliability of the digital certificate and the transactions conducted using the digital certificate is based on the confidence all parties to a transaction have in the structure, policies and procedures surrounding the PKI system under which the digital certificate was issued and subsequently used.

The root certification authority, certification authority and a registration authority are important bodies in implementing the policies and procedures and thus creating the requisite level of trust. 

These bodies act in accordance with the requirements of the certification practice statement and any certificate policies.