Subject: [seamoby] DOS in wireless

From: "Gary Kenward" <[email-masked]>
Date: Tue, 12 Jun 2001 09:32:52 -0400

We all got wrapped up in this discussion of DOS and, in particular, CT
related DOS. It put a smile on my face last night to recall that with
wireless, it is almost trivial to mount a DOS attack without referring
to any protocol nor invading the access network. The traditional term is
"jamming". With the trend to lower power devices, it would not be difficult
nor expensive to mount a fairly widespread, difficult to stop attack (and
I'll stop there).

Perhaps too much attention is being given to putting bars on the windows
when the front door is missing.

Gary

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From: Pat Calhoun <[email-masked]>
Date: Tue, 12 Jun 2001 06:31:55 -0700

> when the front door is missing.

I see your point, but the IESG's concern is that no new protocol introduce
new DoS attacks. We cannot do anything about existing ones, much less physical
ones, but we do have to make sure that we don't open up new holes.

Having said that, given that we expect all data to be protected (and presumably
replay protected), we will be quite safe.

PatC

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From: Arthur Ross <[email-masked]>
Date: Tue, 12 Jun 2001 10:19:00 -0700

>> when the front door is missing.
There was quite a debate on this point in the original CDMA wireless
standarization activities about 10 years ago. The concern was, not only the
malicious prankster/crook, but also the so-called "rogue mobile", meaning
one whose power control has lost it's mind and is no longer properly
controlling its TX power.

The debate has run out of steam, and doesn't seem to be a serious problem
in practice. This may, in part, be due to the fact that a phone that has
lost its power control mind is likely to be seriously broken somehow, or
may run down its battery rapidly, thus leading its owner to turn it off,
take it for repair, or whatever.

The possibility of malicious DoS via plain ol' jamming is always there. The
capacity of a SSMA link is a function of the require received Eb/N0 and the
so-called processing gain (the ratio of the spreading BW to the bit rate).
The effect of a jammer, intentional or inadvertent, is to consume some of
the available capacity, depending on its power, bandwidth, etc.

If anyone wants the long form of this, I can do maybe two hours impromputu
presentation ... anytime, anyplace, anybody's slides! :-)

Then there's always the proverbial Big-Brother-esque spectrum pollution
police .... :-)

   -- ahmr