Dangers of Open Wi-fi Hot Spots

Open and free Wi-Fi spots sound great - internet anywhere!  But what are the IT security dangers?

The internet connects my machine to your machine and lots of other machines as well including good and bad people.   Open wireless networks increases this number of possible untrustworthy connections by forming a local area network that covers the entire neighbourhood and any hackers that might be in the area.   It’s a bit like being in a lift full of strangers – if someone has had garlic or beans for lunch, then it can affect everyone else as well!

 Computers connected to an Open network with no encryption or one protected by WEP all share the same communications stream.  It means that your data is being seen by everybody else's computers as well as your own - those other computers simply ignore the data - this means that it is relatively straight forwards for a hacker to use a program like "Wireshark" to capture a huge amount of information about everyone connected to the open network at the same time.  

WPA and WPA2 are a bit better in that each computer is allocated its own independent communications channel.  The problem however is that even with WPA  connections, it is still possible to fool the system into letting a hacker monitor everybody's communications as well.

Lets say that you've got your phone set up to automatically check emails with your service provider's server and  one day you decide to quickly check the football scores while at a bar with free internet connection.  The phone will detect the connection to the internet and automatically download your emails revealing your personal information to anyone who might be listening on the network as described in my previous post about email security.  The phone also might automatically reconnect to the same network on your next visit to the bar - you could be dancing away to the latest Abba hits and be completely unaware that someone has been able to access your private emails.

It's for this reason of accidental reconnection, that it is generally advised that once you've used a free and open network, that you should use the "Forget Network" option.  This will stop the phone from reconnecting in the future without your consent.

If you need to use wifi hotspots a lot, then it's also a good idea to investigate Virtual Private Networks or VPNs - they work like a tunnel, whereby your connection to the internet is encrypted between the machine that you are using to connect to the internet and the VPN service provider.  Anybody that is locally monitoring your internet connection will just see an encrypted stream of data and will be unable to see its contents.  VPNs might be a pain to initially set up but is worth the extra security.