If you’re using Firefox 3 or IE 7, chances are you might notice that the fav icon (Firefox) and url bar (IE) sometimes turn green.
It is one of the security features from the new browsers, to indicate that the communication between you and those websites are highly secured.
Mozilla has explained it in the Firefox 3 Release notes:
* One-click site info: Click the site favicon in the location bar to see who owns the site and to check if your connection is protected from eavesdropping. Identity verification is prominently displayed and easier to understand. When a site uses Extended Validation (EV) SSL certificates, the site favicon button will turn green and show the name of the company you’re connected to.
If you’re using Firefox3, try these sites and see the differences:
Those having EV certs has owner identity vetted by the CA authorities, while typical SSL certs only performs a validation against the domain name. Please do not get confused that typical certs are not secured. All SSL secured sites encrypts data, but those with EV certs has higher trust as their identify has been “verified”.
So in case you’re wondering how you could change your fav icon for Firefox to be so cool, you’d need to buy an Extended Validation SSL for that to happen.
Extended Validation Certificates (EV) are a special type of X.509 certificate which requires more extensive investigation of the requesting entity by the Certificate Authority before being issued. Source : Wikipedia
For IE Users, details here: