Powderhorn@beehaw.org to Technology@beehaw.orgEnglish · 6 个月前The Math Hack You Didn’t Know Was in Your Credit Cardwww.scientificamerican.comexternal-linkmessage-square7linkfedilinkarrow-up138arrow-down15file-text
arrow-up133arrow-down1external-linkThe Math Hack You Didn’t Know Was in Your Credit Cardwww.scientificamerican.comPowderhorn@beehaw.org to Technology@beehaw.orgEnglish · 6 个月前message-square7linkfedilinkfile-text
I’ve been familiar with the concept, but this is by far the best behind-the-scenes explanation I’ve seen.
The check digit is to catch a mistyped number.