Re: [GNUnet-developers] Fwd: amortizable hashcash paper

[Adam Back]

So I agree the paper is a bit theoretical oriented.

There is an implementation of the basic hashcash mechanism which you
can download and experiment with available here:

        http://www.cypherspace.org/hashcash/

to use the hashcash client to create amortizable hashcash you just do
as Christian described: keep the largest n tokens you've seen (say 10
tokens or whatever) for each document.

(The "resource name" you'd use for hashcash to tie it to GNUnet
documents would be the unique GNUnet document identifier).

Using the hashcash client (it's a command line unix utility) you can
see the effect that you sometimes get a larger collision.

The overall effect is you generally forward around the largest
collisions you've seen for each document and arrive at an estimate of
the popularity of a file.

Users are able (by expending additional CPU resources) to vote
multiple times on the popularity of a document.

Adam

On Sun, Apr 27, 2003 at 09:11:06PM +0300, Igor Wronsky wrote:
> On Sun, 27 Apr 2003, Christian Grothoff wrote:
> 
> > -----BEGIN PGP SIGNED MESSAGE-----
> > I've one little extension that I would propose to the current
> > directory/subspace proposal (http://www.ovmj.org/GNUnet/namespace.php3):
> > popularity metrics. The idea is to use (amortized, averaged) hash-cash as a
> > popularity metric for every signed file. It would work like this:
> 
> If you say so. ;) Your reasoning and motivation sounds good
> but I couldn't understand the paper with a single reading
> and I'm not convinced of its claims. Partly this is due to
> the 'manuscript' or 'sketchy' nature of the work (no offence
> to the author intended), but mainly because I'm not familiar
> with the topic, haven't read the referred papers and do not
> eat modulo arithmetics for breakfast. This might change, of
> course, but don't hold your breath. ;)
> 
> Just my 0.38124 or so cents.
> 
> 
> Igor