This post is about HTTPS (X.509) certificates used on the web1. It has two parts: Certificates explained without cryptography Certificates explained with cryptography The explanation with cryptography depends on the explanation without cryptography, so you’ll want to either read both, or only read Part 1. Certificates and certification authorities, explained without cryptography Websites use certificates to prove that they’re the “real” website2, and not an imposter. The certificate i...| dadrian.io