repost(?): Why i am not truly pseudonymous yet (was: Re: keyword scanning and countering writing style analysis)

Cypherpunks:


I tried to send this message to the cypherpunks in April 1998. 
I suspect that this, and many other messages that i sent, never
reached the cypherpunks list.


If any of you remember reading this, or have a copy of it in 
your archives, please let me know.


Regards,

Zooko


------- Forwarded Message

Date: Wed, 1 Apr 1998 07:06:44 +0200 (MET DST)
From: Zooko Journeyman <zooko@xs4all.nl>
To: zooko@xs4all.nl
Newsgroups: list.cypherpunks
Subject: Why i am not truly pseudonymous yet (was: Re: keyword scanning and countering writing style analysis)
References: <199803252037.UAA06168@server.eternity.org>

Adam:


I think that the state of the art on this is probably close to
the boundaries of the science of machine learning.


I recently saw a presentation by a researcher from Bell Labs.
His machine learning system, which is being patented, had 
success rates better than competing systems (including better 
than a hand-scripted system!) at identifying into which 
categories a phone call or letter to AT&T fell:  "Billing", 
"Subscription", "Complaint", "Delay", "Installation", etc.


Presumably the NSA has similar systems with all of our favorite
keywords.  (Toto: insert funny jokes here.)


Anyway, if _i_ were forced to bet on it, i would say that such 
systems are not yet good enough to reduce the cost of matching
nyms to "insignificant", but that such systems probably _will_
be that good before too long (and our old articles will still
be useful as data then...).


Now the question about counter-measures, i don't know.  (There
is a trade-off between safety and expressiveness here.  We 
could all buy a copy of AltaVista's translator software and
language databases, and then run our missives through a couple 
of pidgin foreign languages before posting them.  [Toto: insert
funny joke about JYA here.])


<sigh>



I think this issue is growing in importance.  I currently use a
very weak nym, which anyone with a little skill should be able
to crack [Toto: bonus points if you _privately_ send e-mail to
one of my eunymous accounts].  I'm starting to think that this
is the worst of both worlds, as potentially malicious sorts are
not significantly slowed down, while potentially beneficient
people are kept a bit more distant from me and are thus less 
likely to be of use to me.  (e.g., people who know me as Zooko
wouldn't notice if "Anna Rosenbaum" (my real name) were to
disappear one night, and vice versa.)


By the way, the reason for my failure should be instructive:  
my nym is so crackable not because of any technical detail 
having to do with remailers or encryption-- it is that 
i foolishly posted articles containing both nyms in the distant 
past, and those articles are now a permanent part of the The 
Net instead of decaying and disappearing like articles from 
even earlier years did.


Another issue for me is the onerous cost of starting a fresh 
nym.  The benefits (true pseudonymity) are uncertain (the bad 
guys' techniques might crack my best effort using current 
technology (especially because of textual analysis as per the
original topic of this message)), and the costs are that i lose
the advantages of concentration of reputation into a single 
nym.


(I've already observed this, a little, with my current set of
weak nyms.  Adding a strong one would only exaccerbate my 
woes.)


A final problem i have with true pseudonymity is that i _like_
meeting people in Real Life, and not only to fight or fuck 
them.




Okay, this has been long and rambling, but i hope useful to 
some of you.  One more point before i go:


There are two ideas of pseudonymity that i have considered.  In
one, you are truly the only person who knows that the nym maps
to your body.  This has obvious advantages, and obvious 
disadvantages.  In the other (which is basically what "Zooko" 
is and was intended to be), there is a large, ill-defined group
of people who also know of the mapping.  This has its 
advantages too-- social advantages (which are very important!),
but the disadvantage is that it is trivially cracked by a mole.



[In fact, i think i recall that about the time "Zooko" appeared
on the scene one "Adam Back" sent me e-mail saying, "Hey--  you
write a lot like Anna Rosenbaum did...  Are you her?".]



[So if anyone wants to do me a favor, look about in your 
archives and dissociate "Zooko" with "Anna".  Thanks!  It might
actually do me some good in the long run, although not, of 
course, against the likes of the NSA.  Perhaps against others.]


Regards,

Zooko

P.S.  For an Nth reason that i don't have a strong pseudonym, 
i never bothered to learn how to use a remailer front-end.  Now
with Xemacs 20 and Mozilla out, i could probably handle it...

P.P.S.  Today i found the 3rd person, including myself, who 
has used the name "Zooko" on the net.

        .----,     |                     mailto:zooko@xs4all.nl
          . /      |    http://www.xs4all.nl/~zooko/public.html
         . /       |   "Any technology which is distinguishable 
        +____.     |    from magic is insufficiently advanced."

------- End of Forwarded Message

Anna Rosenbaum^H^H^H^H^H^H^H^H^H^H^H^H^H^H Zooko wrote:
> If any of you remember reading this, or have a copy of it in 
> your archives, please let me know.

A grep of my old cpunks traffic for 'Why i am not truly pseudonymous
yet' comes up empty, so apparenlty it did not get through.

> [In fact, i think i recall that about the time "Zooko" appeared
> on the scene one "Adam Back" sent me e-mail saying, "Hey--  you
> write a lot like Anna Rosenbaum did...  Are you her?".]

Yep, I recall doing this, except I did not say 'Anna Rosenbaum' but
rather your real first name, which I will of course not mention.  I
recall Tim doing the same (tho' using your initial, and on list),
also, perhaps to Zooko or perhaps to a anonymous post with writing
style and rant topic similarities.

Multiple personality nyms seem to provide some plausible deniability
and doubt, for example people like Monty Cantsin (who's web page
claimed Cantsin was any number of people) and Toto, TruthMonger
etc. whose messages signed by shared keys, or were unsigned.

I reckon there is some room for doubt as to which meat space personas
wrote some of the Toto missives for example.

Probably a good rule of thumb is never to sign anything and always
post via a mixmaster chain.  Some messages don't need a persistent nym
even.  Perhaps one could construct a zero knowledge proof of nym
reputation rating without identityfing the nym which might be useful
for filtering without linkability.

Adam