Google now has encrypted Google web search. Here’s how to enable it in the quick search box in Firefox:
In Mac OS X, edit this file /Applications/Firefox.app/Contents/MacOS/searchplugins/google.xml, (on Windows you should find it at C:\Program Files\Mozilla Firefox\searchplugins\google.xml ). Go to the 7th line and add an ‘s’ after ‘http’, so that it looks like this when done editing.
<Url type="text/html" method="GET" template="https://www.google.com/search">
Save this file and relaunch Firefox.