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The PC Pro guide to wireless

Posted on 28 Nov 2005 at 12:13

Despite the claims of many 802.11g products of 'turbo' modes giving more than 100Mb/sec, we've yet to encounter an 11g product fast enough to stream raw DVDs simply by sharing the DVD-ROM drive in Windows over the network. With MIMO, though, it's a different story. We've had a lot of success using Belkin's Pre-N router and accompanying network card to stream DVDs flawlessly from one PC to another - simply by sharing the DVD drive using standard Windows file sharing - at a separation of about 10m, with a partition wall in line of sight. The trouble is, there still isn't enough spare bandwidth available to be able to guarantee this will work for you, so buying a Pre-N setup purely to stream DVDs might result in disappointment.

SECURITY

As we've already pointed out, you must secure your wireless network as soon as possible after getting it up and running. There are three aspects to wireless security. In order of importance, these are encryption, stealth and access restriction.

Encryption

Encryption is the most important simply because if you use encryption properly the other two are unlikely to matter - your network should be safe from abuse.

There are two standards for encryption over Wi-Fi: WEP (wired equivalent protocol) and WPA (Wi-Fi protected access). WEP is the older of the two, and WPA has come about because WEP simply isn't secure enough. A fundamental flaw in its implementation - to do with the way it appends an extra section on the end of your chosen encryption key - means that over a moderately busy network a snooper can break WEP in a matter of hours.

Until recently, using WPA instead of WEP wasn't easy, since many devices didn't support it, plus comprehensive built-in Windows XP support only came with Service Pack 2. But that's changed now, and we'd advise anyone using WEP to change to WPA immediately. It's easier to set up too; whereas WEP needs a specific-length, impossible-to-remember hexadecimal key, WPA generates its keys from a password that can be anything from eight to 64 characters in length, using any normal characters including spaces. You can generate a long but easy-to-remember passphrase, simplifying things if you're setting up several PCs with wireless connections.

Remember that any encryption system is only as good as its passwords, and that applies equally to WPA. Short or easy-to-guess passphrases are a gift to hackers so, unlike a PIN, a four-digit number is basically useless. A hacker has no limit to the number of passphrases he can try, so yours has to be long and obscure enough that an automated passphrase generator won't guess it.

As well as short numbers, certain things you might think are clever should also be avoided. So, for instance, you might think 'darthvader' is a good one, but in fact every hacker has a dictionary list containing millions of well-known passwords like that. So, 'wallaceandgromit' is out, as is 'frodobaggins'.

Instead, you want a couple of random words, some numbers and some odd characters. For instance, 'cheese672 badger123?' is strong and highly unlikely to be broken by a dictionary attack. A unique sentence - not a well-known quote like 'Ross has a boiler in the living room' - is good too.

Stealth

By default, all access points come pre-configured with a standard name known as an SSID (service set identifier), which the access point merrily broadcasts to all and sundry, allowing clients to see that there's an access point to connect to. This is very useful in Starbucks, but the last thing you want in your home setup. So you should do two things: first, change the default SSID; and second, hide it by instructing the router not to broadcast its presence.