

The Arc Challenge Explained - jgrahamc
http://www.jgc.org/blog/2008/02/arc-challenge-explained.html

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murrayh
A nice explanation for someone who has not looked into Arc (me).

[0-9a-zA-Z]{10} is what, 840 quadrillion combinations? Just out of curiosity,
what happens if we get a 'fnid' collision?

I expect to be serving a few hundred trillion pages in a couple of years time
:-p.

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apgwoz
The article mentions that the fnid could be stored in a cookie. While this is
true it definitely would not be desired, as doing so would make it impossible
to browse the site with multiple windows,each on different pages.

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olavk
And it wouldn't work if there were more than one form or link on a page. Or if
the user clicked the back-button.

