# Public Key Infrastructure
**Aliases:** PKI
**Entity class:** Cryptographic trust infrastructure
## Definition
**Public Key Infrastructure (PKI)** binds public keys to identities through digitally signed certificates and governed certification authorities. Trust anchors, certificate paths, revocation information, policies, identity-proofing practices, and audits allow relying systems to evaluate authentication, signature, and encryption credentials.
## Relationships
- **federal implementation:** [[wiki/Federal Public Key Infrastructure|Federal PKI]].
- **credential carriers:** [[wiki/PIV and CAC|PIV and CAC]].
- **document integrity:** [[wiki/Digital Signature Chain|Digital Signature Chain]].
- **supports:** [[wiki/Identity Assurance|Identity Assurance]] and [[wiki/Machine-Readable Assurance|Machine-Readable Assurance]].
## Sources / Provenance
- [GSA — PKI 101](https://www.idmanagement.gov/university/pki/)