Why "carnivore" type systems can't be (entirely) open source

[Owen Lewis]

----- Original Message -----
From: "Richard D G Cox" <Richard.Cox@mandarin.org>
To: <ukcrypto@chiark.greenend.org.uk>
Sent: 06 February 2001 20:53
Subject: Re: Why "carnivore" type systems can't be (entirely) open source


> > Squidgygate was allegedly ETACS (NB FM) en claire earwigging. There
> > are some grounds to think that it may have been rather more carefully
> > stagemanaged than a casual intercept (i.e. the amateur earwigger was
> > not intercepting the conversation in real time....)
>
> Indeed so.  One of those grounds was that if it had been intercepted in
> real time, only ONE side of the conversation should have been audible!

Not necessarily so. The duplex channel separation is quite small and
depending one one's receiver and other factors, one could quite often get
both sides. The main reason for not getting both sides is that one or other
transmitter would be out of range. For obvious reasons, the antennas on most
amateur scanners are far from optimal.

What one *never* would get is both sides with equal and full clarity. To do
that, one would need to intercept the call with good kit, record the take
and then re-transmit the tape on a single channel. Then there are the
stories of  two amateurs picking up the same conversation independently and
some days apart .....

> Ross had written:
>
> >> I have a whole chapter on this in my book.
>
> Well in that case the sooner we get it in the bookshops the better ...

Seconded.

Owen