From: tcmay@netcom.com (Timothy C. May)
Date: Sat, 7 Jan 95 11:50:42 PST
To: weidai@eskimo.com (Wei Dai)
Subject: Latency Costs of Anonymity
In-Reply-To: <Pine.SUN.3.91.950107103037.10733D-100000@eskimo.com>
Message-ID: <199501071950.LAA22106@netcom17.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


[thread name changed to reflect actual topic]

Wei Dai wrote:

> Note that I SUPPORT anonymous communication, but its costs of bandwidth 
> and latency may be a real obsticle to developing Cryptoanarchy (of the 
> kind described by Tim May) if most people are not willing to put up with 
> those costs.
> 

The good news is that many of the messages that people want
anonymity for are *text* files, e.g., offers of services,
controversial data or opinions, etc. 

There's a kind of tradeoff in size and urgency. To wit, it is seldom
"urgent" that a 1 MB or 100 MB or whatever file get through. (Sorry I
can't draw my favorite little diagram here showing the space of
messages, with "urgency" and "size" as the axes.)

However, I will try such a diagram here:

    ^      ^         
    |      |short                    <---there are very few large files
 URGENCY   |messages                     that must be urgently transmitted
           |
           |
           |
           |                  non-urgent
           |                  huge files
           ---------------------->
             text     books    videos
             10K       1 MB     1GB
                   S I Z E --->

(The tradeoffs are of viewing time, caching, information, etc. A short
message can be _read_ quickly, and hence may need to be transmitted
quickly. The canonical "Attack at dawn" message, for example. A long
message, such as my 1.3 MB FAQ, clearly can be delayed for hours or
days with no real loss, save impatience. My contention is that network
speeds--ISDN, Mosaic usage, faster modems, direct connections--are
being set up and that "urgent-but-small" messages will fit in nicely,
and with low latency through remailers. In the next several years,
that is.)


What this means is that networks of the future, set up to handle huge
files, video-on-demand, etc., will allow text messages to be carried
almost unnoticeably. Interstitially, if you will.

Reordering still requires N messages (whatever N may be), so it is
true that remailer sites must still have some traffic. But this
doesn't have to introduce latencies that are unacceptable.

(If this isn't clear, what I mean by the situation about large files
being shipped is that there should be little cost for users
circulating their own dummy messages through remailer chains. Digital
postage will cost, but costs will drop. Lots of tradeoffs here. No
point in me or any of us trying to anticipate costs, volumes, etc., as
these will evolve and the market will decide.)

--Tim May


-- 
..........................................................................
Timothy C. May         | Crypto Anarchy: encryption, digital money,  
tcmay@netcom.com       | anonymous networks, digital pseudonyms, zero
                       | knowledge, reputations, information markets, 
W.A.S.T.E.: Aptos, CA  | black markets, collapse of governments.
Higher Power: 2^859433 | Public Key: PGP and MailSafe available.
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