From: Carl Ellison <cme@clark.net>
Date: Wed, 22 Nov 95 22:34:06 PST
To: cypherpunks@toad.com
Subject: crypto for porno users
Message-ID: <199511230633.BAA05538@clark.net>
MIME-Version: 1.0
Content-Type: text/plain


I hear occasional uproar from LE types about porno traffickers using strong
crypto like PGP.

[I've been known occasionally to say things for their shock value, but this
time I'm quite serious.]

		------------------------------

As a society wanting to limit the spread of porn, we should encourage those
trafficking in porn to use strong crypto.

1. If two people are sending porn from one to another over the net, the net
	is so insecure that many people along the way could see it.  The
	recipient field could be mistyped, as well.  Either way, someone
	who doesn't want the porn could receive it and be offended.  Strong
	crypto wrapping that porn protects the innocent accidental
	recipient from exposure to the porn.

2. If cops want to track down some pornographer (e.g., because he's dealing
	in child porn), the net and strong crypto provide two opportunities
	to the police:

	a) "no one on the net knows you're a dog" implies that police can
	pose as a fellow porn producer or consumer and get away with it
	more easily.

	b) strong crypto for communications between porn users encourages
	them to speak more freely.  When one of the two is a police officer
	in disguise, that encourages the other (the suspect) to reveal more,
	making the investigation proceed more quickly.  Knowing that the
	crypto is strong enough to keep government eavesdroppers out, the
	sender is given a false sense of security -- is distracted from
	thinking about the trustworthiness of the receiver while thinking
	about the security of the channel itself.

3. Encryption of porn would work against the kind of porn distribution
	found on the alt.binary.pictures.erotic... newsgroups.  Encryption
	requires that recipients be identified.

4. Personal file encryption encourages individuals dealing with porn to
	encrypt and keep personal diaries which might contain evidence.
	Since PGP is subject to brute force passphrase attacks, this gives
	an attack which will open *some* of these diaries.  Without the
	encryption, the suspect is less likely to keep the diary in the
	first place.  This isn't a guaranteed opening into all such
	diaries.  There is no such guarantee possible.  Rather, this
	suggests that strong crypto has a chance to maximize the effective
	"take" by LE forces.


These advantages are balanced against the possibility that there is some
group of pornographers who communciate together, who are identified by the
police, who would be wiretapped *and* who are not infiltrated -- and
therefore whose conversations are unavailable to the police.  The larger
such a group, the less likely it will remain non-infiltrated, so these
groups are probably very small.  There might be some of these -- just as
there might be a few pornographers who have diaries that are encrypted and
unbreakable.  However, strong crypto opens a number of opportunities for
successful investigation -- and it's my guess that in the balance, strong
crypto adds up as a net advantage to the police rather than a net drawback.

 - Carl

 +--------------------------------------------------------------------------+
 |Carl M. Ellison    cme@acm.org    http://www.clark.net/pub/cme            |
 |PGP: E0414C79B5AF36750217BC1A57386478 & 61E2DE7FCB9D7984E9C8048BA63221A2  |
 |  ``Officer, officer, arrest that man!  He's whistling a dirty song.''    |
 +---------------------------------------------- Jean Ellison (aka Mother) -+