From: "Wei Dai" <weidai@eskimo.com>
Date: Thu, 9 Feb 95 17:52:22 PST
To: Johnathan Corgan <jcorgan@aeinet.com>
Subject: RE: a new way to do anonymity
Message-ID: <199502100152.AA29075@mail.eskimo.com>
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Johnathan Corgan wrote:

> Wei, your traffic analysis treatment of this sort of thing would go a long way
> toward uncovering weaknesses and determining operational requirements and 
> limitations.

It seems to me that if a user maintains a 24-hour a day pipe to an 
uncompromised server, then the method I described earlier against 
remailers should not work against that user.  Otherwise, some kind of 
in-out statistical analysis may work.

> Tim, what massive social effects would it have if this type of network service
> were to become widely deployed? :)

See Verner Vinge's _True Names_ for a fictional description of a future 
where real time anonymous interactions are possible.

> At first glance, this Pipe-Net idea doesn't seem to take a lot of rocket science; 
> it seems that most of the components or algorithms are are already in use, just 
> in a very different way.

This is certainly true.  The system Vinge describes is almost a 
pipe-net.  But he didn't say anything about link encryption, without 
which the system can be trivially broken.

> I can think of a number of problems already, however.  Spamming.  Bandwidth
> limitations.  Complexity of client and switch software.  Standards.  Flow
> control.
>
> In other works, all the stuff the ATM forum is already dealing with :)

I haven't responded to the comments you made about the similarity between 
pipe-net and ATM, mostly because I'm not very familiar with ATM.  But 
as I understand it, ATM is based on forwarding fixed length cells, 
whereas pipe-net is based on fixed-bandwidth link encrypted streams.

Spamming, and flow control shouldn't be problems, since all users 
of a server will connect to it with pipes of the same bandwidth, so it 
can just accept a certain number and then stop.

Bandwidth limitations will depend on how fast the server CPU can do 
the encryption and decryption.  With LESM at 100 cps, each connection 
took 2% of the CPU capacity of a Sun 4-CPU(90Hz) 4/670MP.  Of course, 
I made no consideration for efficiency when I hacked ESM, so this can 
probably be decreased quite a bit.

Wei Dai

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E-mail: Wei Dai <weidai@eskimo.com>   URL: "http://www.eskimo.com/~weidai"
=================== Exponential Increase of Complexity ===================
--> singularity --> atoms --> macromolecules --> biological evolution
--> central nervous systems --> symbolic communication --> homo sapiens
--> digital computers --> internetworking --> close-coupled automation
--> broadband brain-to-net connections --> artificial intelligence
--> distributed consciousness --> group minds --> ? ? ?