Certificate Pinning
A mobile-app technique where the client only accepts a specific server certificate (or its issuing CA), even if other certs would otherwise be trusted. Stops MITM attacks but breaks completely if you rotate certs without updating the app.
Source
Related terms
SSL / TLS
Transport Layer Security (TLS) is the cryptographic protocol that powers HTTPS.
TLS 1.2 vs TLS 1.3
TLS 1.3 (2018) is faster (one round-trip handshake) and more secure (removed legacy ciphers) than TLS 1.2.
TLS Certificate (Leaf, Intermediate, Root CA)
An X.509 certificate is a signed document binding a public key to a domain.
Certificate Chain
The sequence of certificates linking your server's leaf cert back to a trusted root CA.
Wildcard Certificate
A TLS cert valid for one subdomain level — `*.example.com` covers `api.example.com` but NOT `v2.api.example…
Let's Encrypt
A free, automated, non-profit Certificate Authority issuing 90-day TLS certificates.