RE: Wireless device vulnerability?

[J Edgar Hoover <zorch () totally righteous net>]

On Sat, 23 Mar 2002, Toni Heinonen wrote:

> > How susceptible are various wireless networking implementations to
> > jamming (as a means to a DoS)?

While several pages of well written technical fantasy may work for
marketing, it's generally not a good idea to try feed fluff to engineering
types.

Let's cut to the chase..

> Executive summary:
<snip>
> With bluetooth, you also have to simply jam on a very wide band (you
> need a very advanced and smart jamming device) or you can have a very
> smart jamming device that jams on the right frequencies on any given
> time.

A jamming device need not be smart or sophisticated.

Choose an inverter IC with the appropriate timings, loop 3 inverters in
series to generate a nice noisy signal on your base frequency. Since it's
a square wave, you'll have lots of useful sidebands and harmonics.

Tuning impedances can selectively create a lot of noise across multiple
wide bands.

Since spreading the noise across more bandwidth decreases the effective
power, an output transistor may need to be added. Swamp the emitter until
it's clipping the signal and producing more power on more frequencies.

Add transistor stages as needed, since each costs about $1.

Just as the Law of Gravity assures us that it will always be easier to
bring things down than it is to put them up, the Second Law of
Thermodynamics assures us that it will always be easier to create chaos
than to create order.

It will always be cheaper to DoS a wireless network than it is to build
it.

There will always be a greater financial incentive to create marketing
hyperbole than to rebut it.