[net.misc] Credit card polynomials?

johnl (12/12/82)

On credit cards the last digit of the card number is usually a check
digit used only for validation.  Does anybody out there know what the
algorithm is?  I believe that most credit card issuers compute it the
same way.

Mail answers to me, don't post to the net.  Ignore the return address
above and use one of the good ones below.  I'll post the answer if
there's interest.  Thanks, as always, in advance.

John Levine, decvax!yale-co!jrl, ucbvax!cbosgd!ima!johnl,
harpo!esquire!ima!johnl, Levine@YALE (arpa).

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