A SSL certificate or Secure Sockets Layer is a security protocol that provides an encrypted link between or server or website and the web browser. It uses a digital certificate that authenticates a website's identity and enables an encrypted connection which secures any online transactions and customer information.
It basically provides a secure, encrypted connection between a user and the website they are using and prevents others from reading potentially sensitive information such as names, addresses, bank card numbers, or other sensitive data.
The process where a secure connection takes place is often referred to as a SSL Handshake and while it looks like a complicated and lengthy process, it occurs in milliseconds, going through the following steps:
1
A web browser or server attempts to connect to a secure website with a SSL certificate
2
The browser or server makes a request for the website to identify itself
3
The website responds to the web browser or server by sending it a copy of it's SSL certificate
4
The web browser or server will check to determine if it trusts the SSL certificate. If it is, it will be signalled to the website
5
The website will send back a digitally signed acknowledgment to initiate a secure SSL connection
6
Data is then shared in a secure and encrypted format between the web browser or server and the website
To determine if your connection to a website is secured using a SSL certificate, the HTTPS or HyperText Transfer Protocol Secure will appear at the start of the website address. If there is no SSL certificate installed, the prefix HTTP will appear instead.
Depending on the web browser which you are using, a padlock icon will also appear in the URL address bar to highlight that the website is secure and will provide details such as:
- The domain which the SSL certificate has been issued for
- Issue and expiry date of the SSL certificate
- The individual or organisation the SSL certificate was issued to
- Digital signature of the certificate authority which the SSL certificate was issued by
- The public key of the SSL certificate