What is a Security Certificate?
A security certificate, also known as a digital certificate or SSL/TLS certificate, is an electronic document that verifies the identity of a website and enables encrypted communication between the server and visitors. It is issued by a trusted Certificate Authority (CA).
How Does Security Certificate Work?
Security certificates work by binding a cryptographic public key to the identity of the website owner. When a browser connects to a site with a valid certificate, it establishes a TLS handshake that encrypts all data exchanged during the session. The browser verifies the certificate against its built-in list of trusted Certificate Authorities to confirm the site is legitimate and not an impersonator.
Certificates come in different validation levels: Domain Validation (DV) confirms domain ownership, Organization Validation (OV) verifies the business entity, and Extended Validation (EV) requires thorough identity checks. Free certificates from providers like Let's Encrypt have made HTTPS accessible to all websites, which is now considered essential for both security and search engine rankings.