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Back then it was a giant pain in the ass. These days isn't it a lot easier to deal with that? You basically just get on the phone with equifax/transunion and u
by jamal-kumar 4y ago
Back then it was a giant pain in the ass.
These days isn't it a lot easier to deal with that? You basically just get on the phone with equifax/transunion and upload some documents.
Guess that trial and error had to start somewhere.
Also I really wonder what the mathematical chances are that the card actually matched with someone back then. Like obviously a collision risk here but how large?
- makeitdouble 4y agoThere's 12 random numbers, and I assume banks reject some numbers based on obviousness (e.g. all 0, all 1s, 1234, all 3 groups are identical etc.) so I'd assume there's actually less probability space than what we'd expect. Even if it's still a pretty huge space.
- nickles 4y agoCredit card numbers aren’t entirely random [0] https://medium.com/@ma.juber/mathematics-behind-credit-debit-card-numbering-340bf68d27d2 https://medium.com/@ma.juber/mathematics-behind-credit-debit...
- makeitdouble 4y agoSorry I think I'm missing it, does that page explain somewhere how the 12 digits that are not set by the MII/IIN and check digit rules are not random ?
- hnbad 4y agoIt says the first six digits are the IIN (and the first one of those is the MII). So if you have fourteen digits, one of which is a check digit and up to six of which are non-random, that leaves only seven truly random digits per issuer, i.e. a pool of 10'000'000 (10^7) numbers rather than the 1'000'000'000'000 (10^12) possible numbers claimed elsewhere. Of course the actual pool is different as the number of fixed digits seems to vary per issuer and for some it seems to be only one.