[hashcash] Re: Possibility of plugin for Mozilla/Thunderbird?

btw David McNab implemented the mint and verify core for hashcash in
python.

I don't know python at all well, but looking at the code I couldn't
see how to use the functions to actually make it format compatible.

http://www.freenet.org.nz/python/hashcash/

Actually looking now I think there is much more code than originally
so probably David has made some more changes.

The comments at the top of the source say:

        1. h != s
        2. len(h) == 20
        3. ((sha(s) xor sha(h)) and (2 ^ q - 1)) == 0

which if accurate wrt the source is not compatible with what hashcash
which does which is (in same terminology):

        sha(1:bits:date:resource:random:count) and (2^(160-q)-1) == 0

(ie tries to make q leading 0 bits in the hash output.

I think also the python code would be vulnerable to the birthday
attack?

Anyway might be useful as a starting point if you wanted to work on
python version.  I think a python version would be useful in general
as lots of unix scripting around linux distros these days seem to be
in python.

Adam

Meredith L. Patterson wrote:
> For my part, I'm glad to learn anything I can. Following Mitch Denny's
> remarks on using hashcash with blogs, I've been thinking about working
> up an XSLT implementation, though I think before that I'm going to try a
> Python port, just to get more familiar with the algorithm.

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