Like most areas of technology, hacking techniques are pretty simple at a conceptual level.
Yet it is the details -- those obscure Internet protocols and arcane terminology -- that make hacking seem difficult.
There are basically just two ways hacking is done in public wifi hotspots.
The first is passive sniffing. Remember that wifi signals are just radio waves. Like any radio waves, all you need is a receiver, tuned to the right frequency, to listen into all the Internet communications at a wifi hotspot.
Of course, every laptop has a wifi receiver built-in -- that is how your laptop communicates. In fact, your laptop already hears all the traffic going on. But, in most instances, it simply ignores all the data that is not intended for your computer.
However, virtually every laptop can be put into something called “promiscuous mode,” which means that it captures all the traffic, not just yours. The real "tech geeks" can do this with settings, but most people just download some software off the Internet to do it.
Thus, any ordinary laptop can be turned into a hacking device. Once in promiscuous mode, all the Internet communications at that hotspot are easily displayed, scanned (e.g., for Social Security numbers or credit cards), or stored for further analysis.
MITM and ARP Attacks
The other way of hacking wifi is called a man-in-the-middle (MITM) attack, and again, the basic concept is simple. They simply set up a false network connection. They get you to connect to it, instead of the safe connection you were looking for. Then, all your Internet traffic will go through their device, before they pass it on to the rest of the Internet.
There are a lot of different ways to set up a MITM attack.
Some are easy to spot (maybe it’s called “Starbacks Network” instead of Starbucks). But most are quite well-hidden and cannot be detected by individuals. Some can even mimic “secure” sites like your bank's website or your favorite online retailer.
Actually, MITM can be used on most networks, even those that you plug into with a wire.
Something called ARP poisoning is one of the other popular techniques, and this visual shows you exactly how easy it is for a hacker to intercept your online communications.
Experts Urge Consumers to Use VPNs
Security experts, and even most wifi hotspot Terms and Conditions, will tell you that there is only one way to protect your Internet communications, and that is by using a Virtual Private Network (VPN).
By using a VPN, all of your communication is encrypted between your laptop and the VPN’s remote server.
We applaud The New York Times for noting recently that our PRIVATE WiFi™ software is a "VPN for the masses," as our software easily protects you from passive sniffing and MITM attacks. If the hacker tries to listen in to your communication, all they will see is gibberish.