Re: Modulus 10 formula (REPOST)

[Douglas Handy <dhandy1@xxxxxxxxxxxxx>]

>I guess everyone knows how to break Mod 10 these days, so 
>banks are getting creative in how they apply it.

I think the original intent of Mod10 was simply to provide a method of catching
keying transposition errors using offline devices like card / diskette punches,
as the operator keyed them.

Mod 10 or 11 or LUHN are still helpful with online entry because it helps to
avoid keying transposition errors where they number might otherwise actually be
a valid number but for the wrong account / product.  For example, I believe the
drug industry has used Mod10 for a long time to help reduce the chance of the
wrong (but valid) product code being entered.

The same can be said of many bar code numbers.

Doug