%include "std.mgp"
%%default 1 bimage "gtk/gtk-window.jpg" 1024x768, center
%page
%charset "iso8859-1"
%bimage "bg.png" 1280x1024

Digest::Hashcash



%pause
	Erzeugung sehr langsam

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	Prüfung sehr schnell

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	Anti-SPAM

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	Rate-Limiting von Resourcen

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Hashcash-Tokens


%font "t5"
   0:040627133051:marc@gtk.org:lUoUt=;&
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   V:   Datum    :  Nutzlast  : Digest


%pause
printf '0:040627133051:marc@gtk.org:lUoUt=;&'
   | sha1sum

%pause
000000e1089a7f9d5fae1304ecbcb59b4ca640de

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Perl


%font "t4"
use Digest::Hashcash;


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$secs = estimate_time $size;
$size = estimate_size $time[, $min];


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$cipher = new Digest::Hashcash ...;
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print $cipher->hash ('marc@gtk.org', size => 24);


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$ok = $cipher->verify ($token);
$bits = $cipher->verify ($token, collisions => 0);
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$time = $cipher->timestamp ($token);
%pause
$data = $cipher->resource ($token);

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Aus!