We’ve come to rely on SSL (Secure Sockets Layer) as our online guardian, protecting our data from criminals and prying eyes by wrapping it up in encrypted data packets. When a closed padlock appears in your browser and the URL in your address bar changes from http:// to https://, that means your data is being sent using SSL.
What is SSL and how does it work?
SSL is a form of public-key cryptography, where both your web browser and the site you’re visiting have a unique public and private key. When you visit a secure website (e.g. https://madecontact.com/), it tells your browser its SSL public key. The website’s key (unless “self-certified”) can be verified for authenticity by a “Certificate Authority” that your browser already knows and trusts.