> > (I regard it as more
> > likely that they were doing traffic analysis and direction-finding than
> > actually cracking the ciphers.)
> 
> IIUC, spread-spectrum communication is not much stronger than the
> background noise, and thus the traffic analysis is not that easy
> either.

We can just speculate here, a practice I dislike, but for fun (hey
today is Friday :) ) I'll add my 2 cent here too.

My first thought while reading this article was: "the seed!"

One thing I assume is that they did not break a cipher, even if
the radio equipment uses DES with 56-bit keys I doubt they had
broken it and can break it in "real-time" on the battle field.

All they say is that they can now coordinate their anti-tank forces
better because they know where Israeli tanks will appear on the battle
field.
This can be done with traffic monitoring and some simple math. formulas
to calculate the directions the tanks drive, plus their distance, and
a lower bound of the number of tanks (at least all communicating peers).

But today military radio eq. use frequency hoping based on a PRNG. This
PRNG is the same in every device and needs the same seed to hop to the
right frequency at the right time.

In the last few weeks during the fights the Hezbollah must be able to
capture zillions of messages which all use the same freq. at the same
time. Maybe they did some statistical magic and were able to guess the
seed of the PRNG based on their observations. Or maybe they get access
to a radio device and were able to reverse engineer the PRNG (or just
connect the radio device to a capture device that uses the freq. the
radio device will use). Or maybe it is just the usual war hoax blah blah,
who knows. :)

Whatever... 

Freq. hoping should protect against jamming only if I remember
correctly. So if I were able to reproduce the PRNG's seed I would use it
to disable the communication between troops during an attack and don't
just do traffic analysis with it. The same result can be accomplished
by let some guys sit in the trees with a spyglass, a compas, and a CB
radio device. ;)

Have a nice weekend,
Thomas






-- 
Tom <[EMAIL PROTECTED]>
fingerprint = F055 43E5 1F3C 4F4F 9182  CD59 DBC6 111A 8516 8DBF

---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]

Reply via email to