Berlin – Online surfers need to be more cautious when using a public wireless internet signal than they would be at home.
That's because, if safety measures are not taken, it's easy for hackers to catch data transfers in public areas.
"Pretty much anyone in the cafe or just nearby can do it," says Erik Tews, a researcher at the Centre for Advanced Security Research in Darmstadt, Germany.
An ongoing scandal in Britain shows the danger. The Guardian reported that British intelligence scanned the email communications of participants at the 2009 G20 conference in London, sometimes at specially set up internet cafes.
But private users are not safe either. Criminals want to access codes, email accounts or online banking. It doesn't take a lot of technical know-how to do so, says Tews.
And it doesn't make a difference if the public Wi-Fi hotspot is protected by a password or not. "That only provides minimal protection," says Tews.
Theoretically, a hacker would first have to decrypt the Wi-Fi code. But, if the Wi-Fi operator makes the code widely available, as is often the case, then it's hard to keep the attacker out.
That means Wi-Fi users are responsible for their own security. The best option is SSL encryption.
"That makes it damn hard to catch something," says Tews. If a connection to a website is encrypted, the address will start with "https" instead of the usual "http." Or there will be the icon of a padlock next to the address. But this option only works if a website operator offers SSL protection.
But SSL encryption only protects the data transferred. It's still possible for hackers to track down who you're communicating with and how often, says Tews.
Using a VPN connection might be the safest option, says Tews. That means all internet traffic runs through a so-called tunnel directly to a third party, rendering it unreadable.
Good, efficient VPN providers cost about $6.60 a month.
But don't just pay attention to what you transmit: also protect what's on your computer. If data has been made available to others in a local network, it might not be long before someone else in an internet cafe is looking at your pictures and enjoying your music and television shows. Turning off sharing is advised.