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Bluetooth Untangled

Cables have the Gadget Master tied up in knots. Will Bluetooth set him free?

Cables are the bane of the modern desk. Mine is a tangle of them, and it’s only getting worse. The latest offenders are the proprietary cable that links my digital camera to a USB port, and another that does the same for my Treo cell phone-except it’s different. My basement is worse: a big box holds one-of-a-kind data cables that I might need some day.

It wasn’t supposed to be this way: Like you, I was promised a universal wireless standard to link my “personal area network” of keyboards, mouses, laptops, digital assistants, and cell phones. It was called Bluetooth.

In 2000, Ericsson unveiled the first Bluetooth device, a $500 wireless headset for laptops and cell phones. Unfortunately, there were no Bluetooth-enabled laptops or cell phones to talk to. Since then, Bluetooth’s rise to market dominance has been nothing short of, well, nothing.

While the 802.11(b) Wi-Fi wireless standard has stormed the consumer and business worlds, Bluetooth has been a dud. But comparing Wi-Fi to Bluetooth is a bit like comparing modems to floppy disks: Both transport data, but that’s where the similarity ends. Unlike Wi-Fi, which was designed for range and speed, Bluetooth was designed to be a battery miser and cheap to implement. It’s like this: Wi-Fi connects your laptop to a network; Bluetooth eliminates cables.

And at last, Bluetooth is increasingly a reality. Palm’s new Tungsten series all feature Bluetooth, so I requested a Tungsten T ($399) to review. Then I ordered an Apple Bluetooth adapter ($54) for my 15-inch Apple PowerBook. And guess what? My new 12-inch PowerBook has Bluetooth built-in. So I’ve got a personal network with three Bluetooth devices. Time to start hacking.

Although Bluetooth sounds very cool, in practice it has two big problems when compared with traditional cables. When you connect two computers together with a cable, you know what’s connected to what. With Bluetooth, you might think that you’re sending the file WarPlans.doc to Colin’s laptop, when in fact you’re uploading it to Saddam’s cell phone. Whoops. The other problem is security: even if you send the file to Colin as planned, Saddam might still listen in.

Most Bluetooth devices get around the first problem with a special “discovery” procedure. Because Bluetooth has an effective range of about 30 feet, you can put your two Bluetooth devices on a table in a big room. If you can be reasonably sure that there are no other Bluetooth devices around, you then wirelessly associate the two devices, optionally typing a common password on both. The devices then learn each other’s Bluetooth Device Address. After that, they can refer to each other by name.

Here’s how it works: when I wanted to sync my Tungsten to my laptop, I turned on the Tungsten, clicked to the HotSync application, and told it that I wanted to set up a Bluetooth connection. My laptop’s name appeared on the screen. I selected the Laptop and clicked “sync.” On the laptop’s screen I got a message saying that a particular Tungsten device wanted to sync; was this okay? I clicked “yes.” Total time to set it up: about two minutes.

Once the wireless connection was set, I found that I could sync my Tungsten with my laptop as long as the two devices were in the same room. Pretty cool! Unfortunately, I can’t figure out how to make the Tungsten automatically sync when I walk into the same room, but hopefully that’s only a matter of time.

To send files between my two laptops, the process was pretty much the same. The first time through, I had to associate the two machines. After that, I could just click “Send File” from Apple’s Bluetooth File Exchange program. A question appeared on the receiving computer asking whether it was okay to receive the transmission.

As Ericsson’s orphaned headset demonstrated, Bluetooth is great-when you have enough devices. So the good news is Bluetooth is beginning to show up everywhere. HP’s new mobile printer comes with a built-in Bluetooth radio, allowing you to print from a laptop or PDA without a cable. Bluetooth connects new GSM cell phones to wireless headsets (now just $89) and Bluetooth-enabled laptops, to serve as a wireless modem. In fact, just as I would no longer buy a laptop without Wi-Fi built-in, I also wouldn’t buy one lacking Bluetooth.

So what about security? The short answer is don’t Bluetooth those war plans. Back in May 2000, Juha T. Vainio at the Helsinki University of Technology evaluated Bluetooth’s cryptography and other security parameters. Although the Bluetooth system provides limited encryption, it relies on custom protocols rather than established ones that had already been subject to attack. If this story sounds familiar, it’s because the Wi-Fi folks did it too.  As a result, security holes were discovered only after the standard was built into millions of consumer devices.

I’m not saying that Bluetooth is not secure, but I wouldn’t trust it with anything confidential. One of the points made by Vainio is that many Bluetooth devices will base their security entirely on a 4-digit PIN code. Even worse: it’s estimated that 50% of all Bluetooth devices will use a default PIN of “0000.”

Bluetooth’s security comes largely from the fact that it is low-power, and thus low-range. If you use a Bluetooth keyboard, a military intelligence official with expensive equipment could probably eavesdrop on your keystrokes from across the street. But for most applications, you’re probably safe. Likewise, if you use a Bluetooth connection from your laptop to your cell phone to go online and do e-banking, most of the security will be handled by the cryptographic connection between the Web server and your Web browser; Bluetooth’s (in)security really shouldn’t matter.

So go out and get your Bluetooth laptop and cell phone. Have a blast! And save your war plans for the land lines.

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