PKI (Public Key Infrastructure)
The entire trust system that makes SSL certificates work, like a network of official agencies that create, manage, and verify digital certificates.
What is PKI (Public Key Infrastructure)?
PKI (Public Key Infrastructure) is the entire trust system that makes SSL certificates work. Think of PKI as a network of official agencies that create, manage, and verify digital certificates to prove websites are legitimate. Just as you need a government system to issue driver's licenses, PKI is the system that issues and manages SSL certificates to keep the internet secure.
How PKI Works
PKI creates a framework of trust that enables secure communications across the internet:
- Certificate Authorities (CAs): Organizations that issue and validate certificates
- Registration Authorities: Entities that verify identity before certificate issuance
- Certificate Repositories: Databases that store and distribute certificates
- Certificate Revocation Systems: Infrastructure to invalidate compromised certificates
- Trust Stores: Collections of trusted root certificates in browsers and devices
Components and Trust Chain
The PKI system relies on a hierarchical trust model where root certificates anchor the entire system. Intermediate certificates bridge between roots and end-entity certificates, creating verifiable chains of trust. This structure allows browsers to validate that any certificate they encounter was issued by a trusted authority, ensuring secure communications across the global internet infrastructure.