Throw away the Internet and start over?

R. A. Hettinga rah at
Wed Apr 23 14:55:45 PDT 2003

Hash: SHA1

At 3:49 PM -0700 4/22/03, Jim Whitehead wrote:
>I saw a variant on this recently (a Microsoft Research project, but
>I don't recall the name), where email senders had to prove they
>performed a
>nontrivial computation before the mail would be accepted. This
>requires the sender to expend resources to be able to send you
>email, but doesn't entail all the messy details of actually
>exchanging money.

It's called "proof of work", and the most commonly cited example is
called hashcash, by Adam Back, which calls for hash-collisions to be
produced by the sender, the idea was further extended into an email
protocol by Eric Johansson called camram.

For me, at least, proof-of-work schemes represent a form of
computational barter, involving disparate computation times on
different machines, and, as we all know, barter evolves into cash
sooner or later.

Besides, the problems of hooking up various bearer-transaction
protocols to the usual book-entry value storage/transfer systems are
mostly imaginary anymore. I expect someone, somewhere, to do
something within the year.

Whether it's cheap enough to use anywhere on the net, much less with
email, will be the interesting thing to find out next...


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R. A. Hettinga <mailto: rah at>
The Internet Bearer Underwriting Corporation <>
44 Farquhar Street, Boston, MA 02131 USA
"... however it may deserve respect for its usefulness and antiquity,
[predicting the end of the world] has not been found agreeable to
experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'

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