4 ms·
It seems like middle initial was also used... she knew the other person was Lisa S Davis but had to figure out what her middle name was.
by dwighttk 10y ago
It seems like middle initial was also used... she knew the other person was Lisa S Davis but had to figure out what her middle name was.
- mjevans 10y agoLet's do some back of the envelope math: 04 bits = Middle initial (It's actually 5, but I imagine the common ones cluster) 10 bits = First Name 10 bits = Last Name 120 bits = 42 adult years (12*10): 3-years ~=1024 slots ~= 10 bits A naive approach might be to add all of these together, except that's unaware of the Birthday Paradox (aka Birthday Problem). https://en.wikipedia.org/wiki/Birthday_problem https://en.wikipedia.org/wiki/Birthday_problem The sets are larger, but even with the addition of those extra 4 bits there's still going to be overlap in a non-trivial population. When is there a "good" chance of a match in all of the fields that matter? What is a "good" chance? What is an acceptable collision? I think most sane people would agree that the final question is the important one. In matters that can derail someone's life and send them to jail an acceptable false positive rate is ZERO. Therefore answering the preceding questions is largely meaningless, we already have example proof of at least one failure, which is enough to declare the system inherently broken.
- CodesInChaos 10y ago120 bits for the birth date is much too big. It's closer to 14 bits (taking your 42 year figure it's log2(42*365)=13.9).
- mjevans 10y agoYou're right, I got confused expanding the number of bits, I'd edit my post... but it seems I can't anymore. shrug That makes the birthday paradox / problem a LOT worse as well.