brainstorming on cpunks' eve

As is mentioned in tims' latest Rant(tm), I've been working on ideas for
creating other cypherpunk services that would be possible to deply to the
net. I've come up with a few, but they are of dubious quality. 

I'm hoping that by posting ideas I know are flawed/of little use that 
followup disscussion might refine them. 

We saw a use for remailers -- to gain a certain anonymity not present in 
cyberspace. How about information drops? How about digital cash drops 
(alt.cash.drop anyone?) I know digicash isn't the rage, and such a
group would probably do zero good for some time, but I'd like to start
talking about the ideas. 

With payments in digicash, you could supply a public key (newly created, 
of course). After the cash is generated/remitted by the other party, 
it would be encrypted and posted to the group. Noone could use the cash
as it sat there, since they can't unwrap the cash. (I like to think of it
as dropping the cash in a sealed envelope). I'm trying to think of both
uses and problems this exhibits. Lots of extra "session keys" is the only
drawback I see. 

Other possible net services: random number services, which don't keep
logs of the numbers it produces -- have it spit a statistically-correct
random stream each time a port is opened? Would this be that useful?

Also, one could set up a hashing/signing service, more akin to a time
stamp service. Mail would be sent to your service, which would attach
the output of 'date' to the bottom of the msg and then +clearsig it. I'm
thinking that chains of two or maybe three reliable machines should be 
used, since all it takes to break this is to change the clock on the
machine you're signing with. With a few (>1) machines, it becomes
very clear that the message was sent at a certain time. Perhaps this 
could be used in the future for "Registered Mail" type exchanges, or 
perhaps as part of a "Digital Notary" system?



As for our media coverage, I'm happy with it so far. I'm willing to bet
digicash that we'll see _television_ coverage re: clipper in the next 
few months. EFF, among others, should be working on that; we've 
already been able to get the word out via newspapers/magazines and radio. 
I wouldn't be at all suprised to see a blip on 20/20 or maybe a 15-second
spot by Tom Jennings & co. before July. 


And projects! I'm currently in the middle of finals, but I'm looking
forward to getting back to work on the things that _really_ matter. 

I was wondering what people were thinking about putting together a 
page for WWW? Would it be useful? Would people browsing around look at
it and would it be a medium to disseminate info? Maybe divide it up...


	RSA, DES, IDEA, 3-DES, etc.

	Clipper, Capstone, Skipjack, Tessera

	PGP, stego programs available, RIPEM, etc.

	EFF, CPSR, Cypherpunks----
			     |media coverage
		             |remailers
			     |stego
			     |voice pgp
			     |clipper projects-FOIAs, bigbro inside, etc.

	other sources of info: sci.crypt, alt.pgp, alt.whistleblowers, 
		alt. privacy, alt.security.



Ideas and suggestions appreciated. 


mt


Matt Thomlinson                               Say no to the Wiretap Chip!
University of Washington, Seattle, Washington.
Internet: phantom@u.washington.edu      	    phone: (206) 548-9804
PGP 2.2  key available via email or finger phantom@hardy.u.washington.edu

Matt Thomlinson:

| Other possible net services: random number services, which don't keep
| logs of the numbers it produces -- have it spit a statistically-correct
| random stream each time a port is opened? Would this be that useful?

	If the random number scheme is subject to evesdropping, which
it would be over todays net, then the numbers you use, while they may
show no pattern, could be known to an attacker, which would probably
make them far less useful.  A better way to spend your time would be to
design a bit of public domain hardware that could be easily built by
anyone who wanted a hardware rng.


| Also, one could set up a hashing/signing service, more akin to a time
| stamp service. Mail would be sent to your service, which would attach
| the output of 'date' to the bottom of the msg and then +clearsig it. I'm
| thinking that chains of two or maybe three reliable machines should be 
| used, since all it takes to break this is to change the clock on the
| machine you're signing with. With a few (>1) machines, it becomes
| very clear that the message was sent at a certain time. Perhaps this 
| could be used in the future for "Registered Mail" type exchanges, or 
| perhaps as part of a "Digital Notary" system?

	If you include the signatures of the previous several messages
in the signed message, and issue each a message ID, changing the time
becomes easier to detect.  If you keep all messages signed that week,
and publish a checksum in an easily found source, say the New York
Times, then you're repeating work already done at Bell Labs.  (I'm
sure someone could find a reference if anyone wants to get in touch
with these folks?)



Adam

-- 
Adam Shostack 				       adam@bwh.harvard.edu

Politics.  From the greek "poly," meaning many, and ticks, a small,
annoying bloodsucker.

> 	If the random number scheme is subject to evesdropping, which
> it would be over todays net, then the numbers you use, while they may
> show no pattern, could be known to an attacker, which would probably
> make them far less useful.  A better way to spend your time would be to
> design a bit of public domain hardware that could be easily built by
> anyone who wanted a hardware rng.

Not really, the receiver of these numbers could run it through several
crypt programs with random keys gotten from his machine, etc.  If you do
several hundred rounds with several hundred random keys with random delays,
the random numbers resulting from all this abuse should be quite different
from anything that whoever is spying on the transmission will see...
 
(Granted, though this would still be a PRNG, it would be better than most,
if the purpose of these random numbers is to simply act as a RN server.)

 
> 	If you include the signatures of the previous several messages
> in the signed message, and issue each a message ID, changing the time
> becomes easier to detect.  If you keep all messages signed that week,
> and publish a checksum in an easily found source, say the New York
> Times, then you're repeating work already done at Bell Labs.  (I'm
> sure someone could find a reference if anyone wants to get in touch
> with these folks?)

I haven't heard about this... can you tell us more?

Matt Thomlinson <phantom@u.washington.edu> wrote:

> Other possible net services: random number services, which don't keep
> logs of the numbers it produces -- have it spit a statistically-correct
> random stream each time a port is opened? Would this be that useful?

Well, I don't know if it's useful or not, but for sake of
curiousity/experimentation, I set up a random number server.  Send mail
to mg5n+random@andrew.cmu.edu and it'll spit out 256 bytes of random
data.  :)

The RNG is the same one I use for my remailer.  The random numbers are
generated from (among other things) taking a hash of a listing of the
users who are currently logged-on, so it's impossible to predict what
will come up from one minute to the next.  (Try fingering
@unix.andrew.cmu.edu)

wcs@anchor.ho.att.com
 (bill.stewart@pleasantonca.ncr.com +1-510-484-6204) wrote:

> For crypto use that's not very helpful - if the numbers go across
> the net, other people can see them.  But they may be somewhat
> helpful as seed material for your own random number generator,
> along with hashes of your memory, random Ethernet traffic, etc.

Right.  Always crypto-launder random number files before and after
each use.  :-)


Bill Stewart wrote (re timestamps/digital notary):

> There's certainly a need for such services.  You have to be
> careful to avoid stepping on Bellcore's work, since I think it's
> patented, but related services may be practical and profitable.
> You have to decide how much you're willing to trust the
> timestamp that the service generated, as you would for a
> human notary.  With a digital notary, there's a risk someone
> could hose the clock on the notary's machine, get something
> notarized, and reset the clock, so even if the notary's being
> perfectly honest it's not risk-free.

This shouldn't be too hard to do.  Considering many of the remailers
already support PGP, it shouldn't be too much work to modify the current
remailers to take a message, add a date/time, sign it with PGP, and send
it back.

Excerpts from internet.cypherpunks: 11-Mar-94 brainstorming on cpunks'
eve by Matt Thomlinson@u.washin 
> I was wondering what people were thinking about putting together a 
> page for WWW? Would it be useful? Would people browsing around look at
> it and would it be a medium to disseminate info? Maybe divide it up...
> 
>         RSA, DES, IDEA, 3-DES, etc.
>         Clipper, Capstone, Skipjack, Tessera
>         PGP, stego programs available, RIPEM, etc.
>         EFF, CPSR, Cypherpunks----
>                              |media coverage
>                              |remailers
>                              |stego
>                              |voice pgp
>                              |clipper projects-FOIAs, bigbro inside, etc.
>         other sources of info: sci.crypt, alt.pgp, alt.whistleblowers, 
>                 alt. privacy, alt.security.
[CRs removed for brevity]

Well, I have a little web site. I'm uploading as much
hacker/cyber/clipper stuff as my quota will hold. Feel free to browse.

URL =
http://www.cs.cmu.edu:8001/afs/andrew.cmu.edu/usr25/jbde/www/matrix/matrix
.html

Have phun!
Jer

darklord@cmu.edu | "it's not a matter of rights  / it's just a matter of war
 finger for Geek |  don't have a reason to fight / they never had one before"
   Code, PGP Key |                                    -Ministry, "Hero"
> http://www.cs.cmu.edu:8001/afs/andrew.cmu.edu/usr25/jbde/www/default.html <

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Jeremiah A Blatz spake:
> 
> Excerpts from internet.cypherpunks: 11-Mar-94 brainstorming on cpunks'
> eve by Matt Thomlinson@u.washin 
> > I was wondering what people were thinking about putting together a 
> > page for WWW? Would it be useful? Would people browsing around look at
> > it and would it be a medium to disseminate info? Maybe divide it up...

	I've been working on adding html to the soda.berkeley.edu
archive. It's still "under construction" and very messy right now, but
it's there.

ftp://soda.berkeley.edu/pub/cypherpunks/Home.html

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