From: dlv@bwalk.dm.com (Dr.Dimitri Vulis KOTM)
Date: Wed, 2 Apr 1997 21:33:05 -0800 (PST)
To: cypherpunks@toad.com
Subject: Re: remailer spam throttle
In-Reply-To: <199703301545.QAA03183@server.test.net>
Message-ID: <wkik5D30w165w@bwalk.dm.com>
MIME-Version: 1.0
Content-Type: text/plain


(I'm behing in responding to e-mail)

> > 4. What if the LEA's decide to find out how K, L are generated?
>
> Random pool like PGP, it's one way and the pool has more bits than the
> key material the Feds have anyway.  /dev/urandom is nice.

Not sure how LEA's work in the U.K., but here in the U.S. they just
might be interested in figruing out the state of the machine when
/dev/whatever was read.  Besides, someone might just use the lc
rand in the C library and init it with srand(time(NULL)*pid()) -
making it worth the while to figure out what the pid might be like.
(Wasn't that the basis of one of thw early attacks on Netscape?)
I say, eschew any protocol that involves generating a pesudo-radom
key, and then discarding it. What if the LEAs want to examine your
hard disk to see how thoroughly it's been discarded?

> > It may be hard to prove a negative to a LEO who doesn't know what
> > the hell you're talking about. You have a file in your spool that
> > was encrypted with a key that your program generated, but now you
> > no longer have the key? Well, tell us how the key was generated.
>
> I think you're arguing for your discard all policy :-)

Yes. You don't have your own domain, so you can't possibly imagine
the kind of idiots that have been getting on the 'net in the last
few years.

By the way: if Alice sends Carol an e-mail via Bob's remailer,
and Bob's remailer uses a third party database to see if Carol
accepts e-mail (such as a key server) then Alice can determine
whether Carol accepts anonymous e-mail.

Say, Carol is a journalist and Alice is a whistleblower. Alice
first sends a ping, which causes Bob's remailer to send Carol
a form letter  explaining how to unblock herself. Alice checks
the database until (hopefully) she sees that Carol accepts
e-mail, then she sends her whatever.

> btw if you're interested to fix the keyserver so that it requires an
> ack to a ping with a nonce, someone at MIT has a fast PGP key database
> / web key server which isn't using PGPs linear lookup.  You can find a
> link to it from Brian LaMachia's keyserver page.
>
> Another snazzy thing to do to the keyserver would be to have it obtain
> a timestamp signature on your key (from a third party time stamping
> service, of which there are several) and include that too.

Sigh - I wish. I'm behind on a bunch of projects, including the great
spambot. Thanks for the info anyway.

---

Dr.Dimitri Vulis KOTM
Brighton Beach Boardwalk BBS, Forest Hills, N.Y.: +1-718-261-2013, 14.4Kbps