Setting up secure connection on your Apache web server is very much straightforward on Linux — all the tools are at your disposal, and in just a few commands, you can be fully set up.
The following instructions are for Ubuntu and CentOS, and covers generating a self-signed certificate.
For an overview of free and cheap SSL certificates, see http://webdesign.about.com/od/ssl/tp/cheapest-ssl-certificates.htm. These certificates from Certificate Authorities only certify that the certificate was issued to the same person controlling the domain. They are fine for internal sites and personal home pages, but not for eCommerce sites..
For an overview of Enhanced Validation certificates (more expensive but more globally trusted), see http://webdesign.about.com/od/ssl/tp/cheapest-ev-ssl-certificates.htm. These certificates are issued against a real-world check of your identity, carrying thus a higher cost and higher trust. They are suitable for high-traffic sites that want to be properly identified and commercial sites; they are overkill for small project sites and testing. Read more