I'm guessing he/she means "coming up with numbers which can't be hacked"?

That is, if I buy a phone card with the number 123-456-789-1, I shouldn't be able to guess that 123-456-789-2 is also valid and get some free credits.

If so, that's an interesting question, though not a Perl question as such.


($_='kkvvttuu bbooppuuiiffss qqffssmm iibbddllffss')
=~y~b-v~a-z~s; print

In reply to Re: Prepaid Cards by Cody Pendant
in thread Prepaid Cards by Anonymous Monk

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