Definition
Certificate Authority
A trusted organization that issues digital ID certificates and can cancel them.
In Depth
A certificate authority works a bit like a passport office for the internet. It vouches for the link between a person or organization and their digital key by issuing a certificate, and it can revoke that certificate if something goes wrong. When your certificate comes from a recognised authority, other people have a solid reason to trust that your digital signature is really yours.
The technical role is the same everywhere. The terminology and legal oversight differ, though. In the EU and UK, a certificate authority that issues qualified certificates is regulated under eIDAS as a "qualified trust service provider," and each region keeps its own official trusted list. The US has no equivalent single legal register.
Sources
- NIST Computer Security Resource Center Glossary (certification authority) - A trusted entity that issues and revokes public key certificates.