From: Tim May <tcmay@got.net>
Date: Sat, 17 May 1997 02:21:27 +0800
To: cypherpunks@algebra.com
Subject: Total Paranoids Don't Need Cryptography
In-Reply-To: <19970515192926.34411@bywater.songbird.com>
Message-ID: <v0300780aafa255fd7571@[207.167.93.63]>
MIME-Version: 1.0
Content-Type: text/plain



May's Second Law of Paranoia: If everyone is out to get you, cryptography
is pointless.

May's Lemma for Remailers: If they are out to get you, and all remailers
are colluding to help get you, then remailers are worthless.


The recent "criticism" of remailers by Kent Crispin is just a manifestation
of these obvious points. Truly, if everyone outside of some agent, Albert,
is colluding with each other, then simple comparisons of what they've sent
to each other must leave what Albert has sent.

(There is still a minor use of cryptography in terms of encrypting diaries,
or records on a machine, for example, even in a world in which they are all
to get one.)

The more interesting issues are the tradeoffs between sizes of collusion
sets, the partitioning of the graphs into collusion sets, and estimates of
remailer entropy in the presence of varying amounts of collusion, low
latency/mixing, etc.

Many of us have of course argued for years that more detailed studies are
needed...Kent observing that if all remailers are colluding one gets fewer
(or no) benefits is hardly original or profound. Cf. the discussions of
collusion by Chaum, Birgit Pfitzman (Eurocrypt, I think in 1989), Hal
Finney, Wei Dai, myself, and others.

"All cryptography is economics." (Eric Hughes)

All remailer security is about economics, about how many colluders are out
there, about the incentives and disincentives they feel to collude (*), etc.

(* Any remailer who seeks to collude will quite quickly become known to
other remailers as a colluder. I think a fairly stable equilibrium is for
nearly all remailers to refuse to collude on general principles, and only
collude in extreme circumstances.)

If critics of remailers like Kent will not even bother to think deeply
about these issues, with some back of the envelope calculations, and with
some perusal of the main papers and articles in the area, I fail to see why
we should take his points with any degree of seriousness.

--Tim May

There's something wrong when I'm a felon under an increasing number of laws.
Only one response to the key grabbers is warranted: "Death to Tyrants!"
---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
W.A.S.T.E.: Corralitos, CA  | knowledge, reputations, information markets,
Higher Power: 2^1398269     | black markets, collapse of governments.
"National borders aren't even speed bumps on the information superhighway."