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Preprints & Reprints Easy Interception It seems to be generally accepted that networks built from copper wires are reasonably secure, whilst those built from optical fibre are incredibly secure, and all things wireless are as leaky as a sieve. Perceptively I think it goes something like this. To break into a pair of copper wires, you need to gain physical access and then by the use of a pair of crocodile clips you can be online and extract any information, audio, video or data as you see fit. Optical fibre on the other hand, presents a far greater challenge in the minds of most people, but the reality is crocodile clips for optical fibre do exist. By merely bending optical fibre over a reasonably tight radius, light leaks out through the cladding and can be detected. The recovery of audio, video or data information without the user knowing is therefore relatively simple once the fibre is accessible. For radio, all you basically need is an antenna and you just suck the information right out of the ether. Of course if you have a microwave radio system, or directed beam of some kind, it means finding the right location so you can actually intercept the waves. But if the system is an omni directional mobile phone, or Wireless LAN, or a PC on a desk that simply radiates energy in all directions, it can all be picked up metres away with relatively unsophisticated equipment, and then it is a different matter. In recent weeks there has been a bevy of Internet publications detailing new software that can crack the wireless encryption protocols (WEP) currently used on LANs. The very fastest algorithms can now decode in less than a second by gathering thousands of samples of repeatedly transmitted information. One of the most commonly published algorithms is called 'Air Snort' which recovers encryption keys very rapidly. In effect all you have to do is passively monitor one transmission after another, make comparisons and gradually the key emerges. All very basic and all very simple. Many people have been surprised that the WEP designers didn't anticipate that this would happen and only specified a 40bit key. The good news is that they actually included a 128bit key, which remains secure for present. Does this all mean that we should stop using wireless transmission? I don't think so; it would be foolish to abandon any technology on the basis of its momentary exposure to interception. The reality is that anybody wishing to intercept communication in any form be it over copper, fibre or wireless has their work cut out to a modest degree. Physical access is the first priority, followed by software having the capability to decrypt the information. For the most part, the majority of communication on this planet enjoys no form of encryption or protection and the interceptions are very small. When compared to the number of conversations that are overheard in a room or on a train, or indeed the number of credit cards that are compromised after handing them to a waiter, hotel reception or gas station attendant, the risk is very small. It would be imprudent indeed not to take adequate precautions with our information and the protection of our commercial interests. The fact that wireless networks can be hacked today in terms of basic access to the network doesn't mean to say that we can't further password protect and encrypt our files and folders prior to transmission. So if you have really important data you do not wish people to access, it's very simple, protect it before you send it. Word count = 598 |