Actually there are three classes of bluetooth:

Class 3 with with 0 dBm (1 mW), 100M or so range (usually as a seperate
dongle, not many devices have this capability built in as it eats batteries,
however several "base station" products do it).

Class 2 with 4 dBm (2.5 mW), 10M or so range (the "usuall" one)

Class 1 with 20 dBm (100 mW) 10cm range (i.e. physically next to something).

Oh wait. What happens if you get a really good antenna and radiate at a much
higher power, hmmm... you can probably talk to bluetooth devices farther
away... Sort of like 802.11.

Plus you need to consider high volume enclosed spaces like elevators,
turnstiles at subways, building entrances, hotel lobbies, airport lounges,
etc. People are already slapping fake fronts/keypads/card readers onto ATM's
to gather megnetic strip information and PIN numbers (allowing them to clone
your card and raid your account), how hard would it be to build a battery
powered bluetooth equivalent?

Kurt Seifried, kurt (at) seifried (dot) org [email concealed]
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http://seifried.org/security/

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