849 karma · joined March 23, 2009
n log (c)
for a length-n password with symbol space c. the huge difference in crack time is because zxcvbn is using c==33 (symbols only) for $^$^$^_ and c==59 (symbols + a-z) for $^$^$^z
$^$^$^i is in the middle -- 'i' is considered a dictionary match, the rest is c==59 bruteforce.
the bigger problem is $^$^$^ isn't recognized as a pattern, but i'm working on ways to improve bruteforce estimation too. good example!
horsebattery vs 'h orsebattery', on the other hand, shows a clear flaw -- it doesn't tolerate misspellings up to a given edit distance. edit distance is tricky because efficient word segmentation gets much harder, especially w/ support for l33t substitutions.
'abcde' vs 'a b c d e' is tricky too. i could add special case for spaces only that would allow zxcvbn to recognize 'a b c d e' as a sequence, but it wouldn't cover 'a-b-c-d-e', 'a8b8c8d8e' etc.
Password fields that are too short cause a similar problem, where you ask "am i still typing? did it cut me off?"
We purposely made the fields huge to help with this on: https://www.dropbox.com/register
A fun extension would be to recognize repeated chunks in addition to single characters.
the forbidden list is: $ < > ^ ! [ ]
* pole
* biosphere
i've had CS and foreign language profs who used their own course notes updated yearly, and i ended up relying on these more than any prescribed textbook. the freshness made a big difference. the profs were also more invested in the material because they either wrote it themselves, or at least took the time to assemble. as such they were clued in to the contents and focused on them in lecture. a batch of notes also has less perceived authority than a textbook, which i think is a good thing, as it encourages questions and challenges.
The author maintains that fats and cheap carbs can only interrupt the body and add to its exhaustion. I think this is true only if you fail to shoot the moon.
i like to run. simple. no gym membership. no complicated/expensive gear -- only necessary investment is a pair of running shoes (runs around $90). best of all, you can exhaust yourself quickly: if you don't have much time to spare, just run faster* for less time.
* i wouldn't recommend taking this to an extreme. i knew a guy in college who'd max out the treadmill for a few minutes, sweat like crazy and call it a day. odds are that's terrible for you. (he also had an anger management problem...related?)