you are viewing a single comment's thread
view the rest of the comments
[–] 21 points 9 months ago (4 children)

Workaround: interpret "and" as "plus", and say a single number which is the two summed together.

  • source
  • hideshow 4 child comments
  • [–] 15 points 9 months ago (2 children)

    Nah, the lowest digit of a credit card is a checksum, and the first few digits identify the credit card company, so it's pretty trivial to narrow down the possible options

  • source
  • parent
  • hideshow 2 child comments
  • [–] 7 points 9 months ago (1 child)

    Standard compliance rules generally allow showing the first six and last four digits on a statement or receipt or whatever. That leaves 6 digits, and since you know it has to match the cksum, 1/100,000 odds on straight guess.

    You may be able to knock down two more digits if you know which bank and card type (debit, prepaid, etc) it is. The first 6 digits used to encapsulate that data but there's a transition to 8 now.

  • source
  • parent
  • hideshow 1 child comment
  • [–] 3 points 9 months ago

    Sure, but in this case we have a credit card number summed with a 3-4 digit number (which you don't have to guess the length bc of the first digits of the processor identificatoon). You can try every permutation of 3-4 digit number taken out, and eliminate all the ones that don't have a valid checksum

  • source
  • parent