Thanks, Gerhard and Peter. By "prefix analysis" I meant IIN/BIN routing and the like; and yes, of course there's Luhn calculation, but if you have a stored PAN, it seems unlikely that you're going to be calculating the Luhn again-you presumably did that when you got it, no? But I suppose some poorly designed application might not get around to it until later. BTW, the Luhn is calculated on ALL the preceding digits, not just the remaining.
Gerhard: you wrote: >Keeping the number in unsigned packed form can speed verification How is x'123F' faster to verify than x'123C'? How does packed format help with Endian conversion? Never having really worked with little-Endian, it always makes my head hurt. Also: >unsigned hex was a compromise When you say 'unsigned hex', do you mean x'0123'? or x'007B'? Not clear to me... ...phsiii ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
