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

[Owen Lewis]

----- Original Message -----
From: "Brian Gladman" <brg@gladman.plus.com>
To: <ukcrypto@chiark.greenend.org.uk>
Sent: 08 February 2001 00:25
Subject: Re: Why "carnivore" type systems can't be (entirely) open source


> From: "Owen Lewis" <oml@eloka.demon.co.uk>
> To: <ukcrypto@chiark.greenend.org.uk>
> Sent: Wednesday, February 07, 2001 9:26 PM
> Subject: Re: Why "carnivore" type systems can't be (entirely) open source
>
> > STO has, for convenience, been adopted in this thread as the acronym for
> > 'security through obscurity'. Had not the medium strength cipher in GSM
> > been protected for many years from cracking by the fact that it took
> > determined,
> > knowledgeable outsiders that long to penetrate the obscurity of the
cipher
> > design, GSM's privacy would have been breached at will by all the heavy
> > private dicks and minor govt snoops who would have loved to have done
so.
> > It is STO and some pretty fine calculation of the delay to a crack that
> should
> > be caused thereby that made GSM the success it has been.


> You cannot know how fast or how slow others have been in finding the
> weaknesses in the GSM cryptography.

As you will know, expert prognoses of that type are continually made by
those competent to do so. Sometimes, when they have prognosticated
incorrectly, that failure becomes public knowledge some considerable time
after the event. The public have never (yet) got to hear of their successes.
In the case of GSM, the cipher + STO held up for very nearly the required
time; close enough not to matter and to be counted a success, IMO, given the
limited purpose for which it was only intended.

> As I have said before, people on this list are educated enough to work out
> the motives and the consequences of deploying a weak cipher in GSM.

You have indeed. If I may say so, the error I see
in your position is to assume that 'security' is monolithic and therefore it
is
something one either has or one does not. The truth is more subtle. You are

of course entitled to your view and the world is also free to continue,
regardless, turning in the way that it does.

I have no axe to grind in this matter. However, cryptography is a field of
increasing public benefit as the explosive growth in electronic
communication continues. Many in this list work in fields where they either
influence or are influenced by the cryptosystems of today and tomorrow.

That there is a place for very strong cryptography in the larger world
beyond govt service is clear and tacitly admitted by all except the
blindest, most totalitarian of govts. Nevertheless, the idea of fully secure
systems for mass communication remains simply a snare and a delusion. Were
we ever to have such, we, as a community, would lose more than we could gain
from them. Also, very few of us could properly maintain for ourselves a
fully secure state. Therefore, many would continue to live with less than
full security, clutching something rendered by ignorance or neglect to not
much stronger
than Linus's security blanket.

Last and by no means least, no group we freely elect and charge with our
governance (i.e. communal security and well being) are going to permit such
a fully secure mass communication system to be fielded. There is no sign of
a popular call for such and without a clear majority in favour it will not
happen; perhaps not even then. By and large I avoid the
position of those who insist what others should have 'for their own good'.
People generally understand well enough what will suit them and what will
not.

So, I prefer to take the world as I find  it, nasty as it can be; to make
those parts of my concern work as best I am able and not to be influenced in
what I do by any hypothesised nirvana.

> It was the communications functionality that that made GSM a success. It
> seems to me extremely unlikely that its security (or lack of it) had any
> significant impact on its success one way or the other.

Which aspects of functionality had you in mind?

Owen