What are the core components of a PKI system?

At its core, a PKI system consists of a small set of technical components and supporting policies that together make it possible to issue, validate, and revoke digital identities at scale.

The essential building blocks:

• Certificate Authority (CA): Issues and signs certificates, forming the trust anchor for everything built on top of it.
• Registration authority: Verifies identity before a certificate request reaches the CA.
• Certificate and key repository: Stores issued certificates and associated metadata for lookup and management.
• Revocation infrastructure: OCSP responders and certificate revocation lists that allow relying parties to check current certificate status.
• Governing policies: Certificate policies and certification practice statements that define exactly how the technical components are permitted to operate.

These components apply whether a PKI is a small internal deployment protecting a handful of devices or a large, multi-tenant platform such as primeID CERTIFY issuing certificates across an entire enterprise.