Software → Security
Certificate Authority
A trusted entity that issues and signs digital certificates used to establish identity.
Motivation
Certificate authority solves the problem of deciding whether a public key belongs to a claimed identity.
Where it fits
Certificate Authority belongs to public-key infrastructure and TLS.
Mental model
A CA signs certificates so clients can verify that a domain or entity controls a public key.
Common mistakes
- Assuming certificates encrypt traffic by themselves.
- Ignoring trust chains and certificate expiration.
Related concepts
Certificate Authority connects to digital certificate, TLS, HTTPS, and public-key cryptography.