21st Oct 2008 - 00:00
Abstract
We recently reported on the hotel chain in the US that had its WiFi hacked putting the information of guests and customers at risk. With JD Wetherspoons, McDonald's, Costa Coffee and Regent Inns all offering internet access we look at how a secure WiFi connection can be maintained.
Access to the Internet via public "hotspots" is growing and will continue to grow as more and more hotspots are made available. We have McDonalds offering free Internet access and even Boris Johnson proposing that London becomes a WiFi city with free WiFi. This free bandwidth does come with an element of risk. Once you are associated to an access point, you will be on the same network as others and finding out who else is connected is easy to do. From there an unscrupulous user could try and access your machine. This may not be deliberate - a virus may automatically be scanning in the background and trying to infect other machines. In addition to the possibility of direct attack, your data is probably going to be easily read with little encryption and protection. So what are issues we face when using public 'hotspots'? 1) Clear text data – by its very nature a hotspot will not have any encryption or security on it. It is there to enable as many people as possible to connect, as easily as possible. To offer a pre-shared security key is impractical, and the more people have a key, the less valuable a key is. What does this mean? Well if you are sending email, someone on that network will be able to see, and read that data. It is a bit like handing a postcard over a post office counter. Everyone in the post office can read it. So you really would not write anything confidential on it. To say "Hi, having a wonderful time, wish you were here" is not exactly top secret. But you may not want to put all your credit card information on it. 2) Most web traffic is, by its very nature clear text. Most web sites will switch to secure, encrypted HTTPS traffic when doing commercial transactions. Web mail such as Hotmail, Gmail and Yahoo are normally in the clear. How can you tell if you have changed? Look for the little padlock in your browser. 3) If you are using business email, we strongly recommend using a VPN (Virtual Private Network) between you and the business mail server. This should be provided by the business. This normally is a security overlay on your traffic. This will encrypt data and ensure no eaves dropper reads it. 4) Your PC needs to have a personal firewall installed, and switched on. A basic firewall is provided within Windows now. Use it! This stops unauthorised access on to the PC. 5) Many businesses will add an additional personal firewall. The clever ones will actually change the policy based upon your location, which will control the flow of data in and out of your PC in accordance with your policy. 6) Ensure your anti-virus software is installed, up-to-date and working. This will defend against known virus or 'Trojan' attacks. 7) Turn off ad-hoc networking – WiFi has two methods of working – ad hoc and infrastructure. Infrastructure is when your PC connects to an Access Point, and then on to a wired network. Ad-hoc is when two PC's communicate to each other directly without an Access Point. You really should ensure no one can network directly, unless there is a specific reason. 8) Shoulder surfing. Always be aware who is watching you. Don't sit with your back to a crowd or window inviting unwanted snoopers to see you type your password or read your documents. 9) Think about the length of time you are connected. As a precaution, prepare messages off line and only connect to send and receive. This will reduce the window of opportunity for someone to capture your data. 10) Lastly, when accessing a hot spot be aware of hot spot high jacking. This is when a fake access point is used to fool you into connecting to it. It will record all traffic from your system. This type of attack is mainly used in internet cafes since access is open. Always try and make sure you connect to genuine access points. For more information on security and WiFi visit www.gss.co.uk
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