Update: You need to know how to ban MAC addresses on your router, as you will eventually have a neighbor swamp your network with bittorrent. If you can do that simple operation (usually via your router’s web-based admin), open wi-fi is the right thing to do.

A few months back, I took the password off my WiFi router, and opened it up to the world, with SSID yes_we_are_sharing. Why?

The best answers are given by security expert Bruce Shneier – why open wireless. The second best answer is that Tor hacker Jacob Applebaum also runs open WiFi.

Here are my answers, and the reasons why you should join us.

What’s changed?

The only difference between an encrypted wireless network and an open wireless network is that the part between your computer and the router is no longer encrypted by the router. Anyone can listen in, and anyone can connect to your router and access the big wide Internet.

The part between your computer and your router is only a tiny part of the journey your data takes between you and, say, your online bank. None of the part after the router has changed; if it was encrypted before, it still is, and if it wasn’t is still isn’t, and you should fix that. Read one for how.

Reason: It’s nice

Have you ever used anyone else’s open router? Maybe one named ‘dlink’, ‘linksys’, or a Mac AirPort? I bet you were happy that was there for you. When you move into a new home, when you have problems with your connection, or simply when you’re out and about, it’s great to have a free network. Opening up my network is my small way of giving back.

Myth: Bad people in your front garden

The first question most people ask about open wifi is this: What if someone uses my connection to do something bad?

To use your connection, they would have to be a direct neighbour of yours, or sitting outside your house.

Isn’t it more likely they would go that extra block to the warm and dry coffee shop?

Do you hear of coffee shop owners going to jail much? What about the ‘dlink’ and ‘linksys’ people? “Bad People” typically have their own Internet connection.

Real Risk: Eavesdropping

You might be worried that other people will steal your secrets. Again, they’d have to be sitting in your front garden.

There’s a much better place to steal people’s online banking data, than your front garden: in a coffee shop, at a conference, or, best of all, in an airport.

Reason: It makes you safer

You should setup your machine so that all your connections are encrypted, wherever you are. Opening your home wireless gives you that extra discipline.

• Secure your web browsing. When doing anything senstive, make sure you are using the ‘https’ protocol (your browser will be showing a padlock).

• Secure your email. If using webmail, make sure it’s over https. GMail, to Google’s great credit, has that as the default. If you are using regular email, makes sure you use the encrypted protocol – IMAPS or POPS.

• Secure you IM conversations. Google Talk is encrypted if your client supports it (Pidgin does). Skype is encrypted. As far as I could tell, Yahoo Messenger isn’t, so avoid it.

Weak Risk: Your neighbourhood hacker

If you’re using Windows, you should be running a personal firewall on your machine. I believe there is now one built-in to Windows. Make sure it is switched on.

Administration

Most computers will auto-connect to any available wireless network when they start up. If you notice the same machines on your network every day for a while, they are probably auto-connecting. You’ll need to add rules to your router to ban their MAC address, shunting them back to their own router.

The point of open wireless isn’t to make your neighbours Internet connection redundant, but to temporarily help people out. Your neighbours don’t want to use your connection, as their’s is typically faster for them (they are closer to their router).

Happy sharing!