Kent Lawson with Private Communications Corporation says there's a general rule of thumb in determining whether a public Wi-Fi connection is secure.
"The best rule of thumb is to know that's it's not secure. Because virtually all public Wi-Fi is completely open and completely vulnerable to a wide variety of hacks, and you should simply assume that public Wi-Fi is a very, very ... it's like shouting from a rooftop. Public Wi-Fi is a completely insecure environment."
Lawson says while hackers may not be able to get in and look around in your computer, they can capture everything that's transmitted.
"Wi-Fi is just radio waves, after all. It's just like your station! Anybody with a radio receiver can get this interview, and similarly, anybody who is sitting within radio range of a Wi-Fi hotspot could intercept everything that's being transmitted. There are a couple of classic ways of doing it: one is called sniffing, where you listen to all the communications that go on in a Wi-Fi hotspot. Another technique is called a rogue hotspot where somebody sets up what seems to be a reasonable-sounding hotspot name — something like FreeO'Hare Wi-Fi or something like that. Everything that's being transmitted can be intercepted and stored on somebody's computer for later analysis."
That data can be scanned for credit card numbers, social security numbers, names, addresses and phone numbers. Lawson says public Wi-Fi is here to stay, but it's up to users to protect themselves. And it's more than just having the correct settings on your mobile device.
"Probably most people already have anti-virus and firewall on their devices. Unfortunately, that software really just protects the device. It does not protect the communications. And in order to protect the communications, you need to have what's called a personal VPN, or Virtual Private Network, which is a service that you can utilize to protect your communications in Wi-Fi hotspots."
A VPN encrypts data to and from your device, through a third-party server. Lawson says he'd love to see that kind of protection built in to new devices.
"It's interesting you say that. Yes, we are talking to a number of different manufacturers about doing exactly that. But for now, it's the individual's responsibility to protect themselves. And they can't rely on the hotspot, they can't rely on the web site they visit. They need to protect their own communications using a VPN."
VPN protocols are available for most platforms, and many have VPN support built-in. Additionally, double-check the settings on your device. Make sure your firewall is enabled. In fact, Windows will enable its firewall settings by default if you tell it to during set up. Turn off all sharing. And keep your software updated.