What is SSL? SSL Certificate Basics

Overview

What is SSL? SSL is an acronym for Secure Sockets Layer, an encryption technology that was created by Netscape. SSL creates an encrypted connection between a web server and a web browser allowing for private information to be transmitted without the problems of eavesdropping, data tampering, or message forgery. The use of an SSL server certificate on a website is usually indicated by a padlock icon in a web browser such as Internet Explorer or Firefox.

Millions of online businesses use SSL certificates to secure their websites and allow their customers to place trust in them. In order to use the SSL protocol, a web server requires the use of an SSL certificate. SSL certificates are provided by Certification Authorities (CA).

Why do I need SSL?

If you are transmitting sensitive information on a web site, such as credit card numbers or personal information, you need to secure it with SSL encryption. It is possible for every piece of data to be seen by others unless it is secured by an SSL server certificate. Your customers won't trust your web site without it.

What is a certificate authority (CA)?

A certificate authority is an entity which issues digital certificates to organizations or people after validating them. Certification authorities have to keep detailed records of what has been issued and the information used to issue it, and are audited regularly to make sure that they are following defined procedures. Every certification authority provides a Certification Practice Statement (CPS) that defines the procedures that will be used to verify applications. There are many commercial CAs that charge for their services (VeriSign). Institutions and governments may have their own CAs, and there are also free CAs.

Every certificate authority has different products, prices, SSL certificate features, and levels of customer satisfaction. Read our certificate authority reviews to find the best CA to purchase from.

How do SSL Certificates compare between certificate authorities?

Verisign certificates are better because they cost so much more, right? Not necessarily. You can get a certificate for $100 that does that exact same thing as a certificate sold for $800 from another certificate authority. It is the exact same SSL encryption.

Why the difference? Trust is the biggest difference. Since VeriSign has been around for longer than other certificate authorities, more people trust them so they can charge more. You are essentially paying for the brand.

What is browser compatibility?

The certificate that you purchase to secure your web site must be digitally signed by another certificate that is already in the trusted store of your user's web browsers. That way, the web browser will automatically trust your certificate because it is issued by someone that it already trusts. If it isn't signed by a trusted root certificate, or if links in the certificate chain are missing, then the web browser will give a warning message that the web site may not be trusted.

So browser compatibility means that the certificate you buy is signed by a root certificate that is already trusted by most web browsers that your customers may be using. Unless otherwise noted, the certificates from all major certificate providers listed on SSL Shopper are compatible with 99% of all browsers.

How many domain names can I secure?

Most SSL server certificates will only secure a single domain name or sub-domain. For example, a certificate could secure www.yourdomain.com or mail.yourdomain.com but not both. The certificate will still work on a different domain name but the web browser will give an error anytime it sees that the address in the address bar doesn't match the domain name (called a common name) in the certificate. If you need to secure multiple sub-domains on a single domain name, you can buy a wildcard certificate. For a wildcard certificate, a common name of *.yourdomain.com would secure www.yourdomain.com, mail.yourdomain.com, secure.yourdomain.com, etc... There are also special certificates such as Unified Communications (UC) certificates for Microsoft Exchange Server 2007 that can secure several different domain names in one certificate.

What is a site seal?

A site seal is a logo that you can display on your web site that verifies that you have been validated by a particular certificate provider and are using their SSL certificate to secure your site. It can be displayed on secure and non-secure pages and is most appropriate on pages where customers are about to enter their personal information such as a shopping cart page but they can be displayed on every page to help build trust. Every certificate authority's site seal is different and some look more professional so you should consider what the site seal looks like in order to maximize customer trust.