Open the Tunnel Via Your Laptop
Setup is now finished. In future, before you leave your house or office to work remotely, make sure that the Ubuntu computer is booted up and that you've logged in to it. Then follow these instructions when you reach your destination.
1. Log in to the public Wi-Fi service that you want to use.
2. Start PuTTY, and select the new entry that you created in the list of Saved Sessions. Click the Open button to start the secure tunnel connection.
2. The first time you do this, your system will inform you that the host key is not in the Registry. This is fine--just click Yes in the dialog box that appears to add the host key. This dialog box will not appear during future sessions.
3. Every time you log in using PuTTY, a window will appear bearing the words Login As. Enter the username for the account that you created on your Ubuntu computer, and enter the password when prompted. You'll then log in to the new computer and be shown a command prompt, but you don't have to type anything there, and you can minimize the PuTTY window to get it out of the way. However, you must keep the PuTTY window open in order for the tunnel to work.
4. Start Firefox and select the proxy entry that you created earlier from the FoxyProxy Basic entry on the Tools menu.
And that's it!
From this point on, you'll be browsing via your own secure tunnel. To confirm this, open another browser (such as Internet Explorer) and visit WhatsMyIp.com. This site will display the public IP address of the Wi-Fi service you're using in the coffee shop.
However, visiting WhatsMyIp with Firefox will show a different IP address--the one for your home or work router, which is feeding you the Websites via the secure tunnel. In other words, all of your Web data is coming to you via this IP address, through the secure tunnel. To anyone snooping on the connection, the data will consist of encrypted garbage.
When you've finished working remotely, you can close the PuTTY window, and switch Firefox back to a nonproxy connection by clicking FoxyProxy Basic, followed by Completely Disable FoxyProxy on the Tools menu of Firefox.
Keir Thomas has been making known his opinion about computing matters since the last century, and more recently has written several best-selling books. You can learn more about him at http://keirthomas.com. His Twitter feed is @keirthomas.