4 ms·
Aside from the top two passwords (~17%), the distribution is not so bad. The next five passwords are only 5% of the distribution, which is much more reasonable.
by slavik81 8y ago
Aside from the top two passwords (~17%), the distribution is not so bad. The next five passwords are only 5% of the distribution, which is much more reasonable. With 10^4 possible combinations, these obviously weren't designed to prevent a brute-force attack on their own. For example, with bank accounts the bank card provides a second factor and access attempts are monitored.
There's also little point in hashing a 4-digit PIN. If the PINs were perfectly distributed, it would only take an average of 5,000 guesses to find the original PIN given the hash. Of course, this analysis has shown that they're anything but perfectly distributed; a quarter of them would take less than 20 tries.
- nine_k 8y agoAFAICT, brute-forcing of short PINs is usually prevented by locking up after a few failed attempts. E.g. with a phone SIM card's PIN, you theoretically have the laughable space of 10000 variants, but you only get to try 9 times, the 10th should either be correct, or the SIM card stops working. This gives you about 1% chance of guessing right. With trying the common PINs first, likely maybe 10% chance. Still makes an attempt to break in impractical in very many cases.