[OT] programming question

Smylers Smylers at stripey.com
Thu Apr 26 06:56:47 BST 2007


David Cantrell writes:

> > So what's the best way to randomly permute the order of the answers,
> > store a small amount of state in a hidden field in the form, and
> > reproduce the permutation back on the next call to the server, such
> > that it can map back to the original answer order, without (too
> > much) information leakage?
> 
> md5(correct answer plus sekrit) inna bun^Whidden field

That's what I was about to suggest, too.

But it does have the disadvantage that while you can tell whether the
user was correct (and you can inform them what the correct answer for
the question is), you can't give feedback like:

  Sorry, that's incorrect.  You chose "Foggy" but the correct answer is
  "Compo".

Which may or may not be important.

Smylers


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