In today’s security-conscious society, yacht owners can spend millions on security features like one-way bulletproof glass, anti-Paparazzi lasers, armed guards and diver detection systems. But how many owners have given much thought to the young stewardess lounging with her laptop on the boat next door, or to the tourist apparently tapping out an email at a dockside café?
Picking up signals
One objective of a good wireless network system is to provide a strong signal, but that strong signal can be very attractive to those looking for a convenient Internet connection or a free phone call. A strong wireless signal without a strong defence against unauthorized access also provides an open door to those with more sinister intent.
If a crew member on the boat across the dock wants to use some of your bandwidth, he or she might find few barriers to joining your network. Nearly everyone knows how simple it is to connect to the yacht’s wireless: click the name of the network and enter the password… voila! Welcome aboard. Most consumer-grade networking hardware is designed to be just that simple. But the transparency of the connection process doesn’t come without risk.
All wireless connections, except for a rare few that use infrared or laser light, are radio links. A wireless card contains a radio transmitter and a receiver as does the wireless access point (WAP) itself. And like all radio signals, anyone with a receiver can listen to what’s being broadcast.
Unfortunately, there are many low-cost and even free programs available to anyone who wants to try their hand at electronic surveillance for fun or for profit
Wireless network signals are not very powerful, but they do a very good job of providing a data connection to another receiver and transmitter within 150m or so.
Since the wireless transmitters used in most portable devices are omni-directional, the antenna doesn’t have to be pointed toward the receiver. Wireless data is carried on microwaves that are very short, a little less than 13cm long. Compared to a short-wave radio signal with a wavelength as long as, or longer, than the yacht itself or an FM radio wave that is about 3m long, such short wavelengths can penetrate almost any enclosure to form a cloud of radio waves around the yacht.
Unauthorized network access by someone looking for an Internet connection or just trying to log on for the fun of it might not seem all that threatening. At least no more than an unknown dock walker sneaking down to the crew mess to have a look in the fridge or rummage through the movie selection. How much harm could they do?
From the aspect of the yacht’s network security, if they made it to the crew mess they may find it just as easy to check out the owner’s safe or the yacht’s credit card files.
The risk of becoming a victim of electronic data snooping is very real, and it doesn’t take a sophisticated operative with racks of high-tech electronics to open the door of a yacht’s virtual vault.
Unfortunately, there are many low-cost and even free programs available to anyone who wants to try their hand at electronic surveillance for fun or for profit.
One of the earliest, but still very useful, examples is NetStumbler. This 10 year-old program works on a laptop or Windows CE-based device and displays wireless access points, SSIDs (the name of the local area network or LAN), MAC address (a code to identify a network interface device), channel, type of encryption, and signal strength. When this software is used on a GPS-enabled device, it can map the location of nearby WAPs.
NetStumbler provides a casual snooper with a great deal of useful information. It will clearly show who has the strongest and most vulnerable signal within range.
This article was first published in the June 2011 issue of Dockwalk