Live data from Hacker News

Zxcvbn: realistic password strength estimation

tech.dropbox.com

21–30 of 134 posts

Re: Zxcvbn: realistic password strength estimation

#21
post #14

FJFJFJFJ takes "centuries"? Probably needs a little more tweaking.

It certainly needs more tweaking. FJ, FJFJ, etc isn't in any of the 10k passwords people commonly use, isn't a sequence, isn't a single repeated character, etc, so zxcvbn recognizes it as bruteforce.

A fun extension would be to recognize repeated chunks in addition to single characters.

Re: Zxcvbn: realistic password strength estimation

#22

Earlier quoted context omitted.

Did hindi take "guess" as a loanword or is that just a massive coincidence

Loan word. I can't remember the the Hindi word for "guess" right now. PS: Although I don't remember the exact words but there were some which are strikingly similar in both languages. But I found this for you. http://en.wikipedia.org/wiki/List_of_English_words_of_Hindi_...

> I can't remember the the Hindi word for "guess" right now.

Bujho.

Re: Zxcvbn: realistic password strength estimation

#23
post #21
post #14

FJFJFJFJ takes "centuries"? Probably needs a little more tweaking.

It certainly needs more tweaking. FJ, FJFJ, etc isn't in any of the 10k passwords people commonly use, isn't a sequence, isn't a single repeated character, etc, so zxcvbn recognizes it as bruteforce. A fun extension would be to recognize repeated chunks in addition to single characters.

One thing would be to try to measure entropy in a different way, e.g. run gzip on it. Right now FJFJFJFJ has the same entropy as FJGJFJGJ.

Re: Zxcvbn: realistic password strength estimation

#24
post #2

> Bank of America doesn’t allow passwords over 20 characters, disallowing correcthorsebatterystaple. Passwords can contain some symbols, but not & or !, disallowing the other two passwords Can anyone elaborate why "&" or "!" wouldn't be allowed?

The ampersand (& symbol) might make sense due to the following fact: a form is usually submitted as urlencoded:

     name=drostie&password=wining%20%26%20dining%20the%20suckas!&language=en-US
and they might be worried about some browsers not correctly URLencoding such a form field -- or else they're perhaps worried that their own URLecoding decoder will break.

The exclamation mark is weirder -- I can't think of a deep need to escape that symbol. The + symbol, maybe, since sometimes + in a URL is supposed to be used as a replacement for %20 as an encoding for a space, but not the ! symbol.

Re: Zxcvbn: realistic password strength estimation

#25
post #16

I hate when they won't let me use a password that's not "strong" enough. I picked my password, let me use it. I know the consequences of using an easy password.

I hate when they won't let me use a password that's too strong. Nothing makes less sense to me than rejecting a password because it contains '!' or '#'.

I cringe every time I see this happen... and always with websites where you -want- stronger passwords.

Re: Zxcvbn: realistic password strength estimation

#26
post #8

Earlier quoted context omitted.

A not-very-great but traditional way to avoid some kinds of security holes is to sanitize your input by blacklisting anything that could be a shell/scripting/SQL metacharacter. Seems restrictions like that are still pretty common, either because it's actually still needed for security (alarming if true at BoA), or because it's now a sort of cargo-cult thing.

sounds about right. screenshot of BofA's policy here: http://dl.dropbox.com/u/209/bofa_password_constraints.png the forbidden list is: $ ^ ! [ ]

Huh, thanks! I suspected it was a security thing, but I've seen some sites where other non-alphaneumeric characters were disallowed as well. :/ At least this makes some sense.

Re: Zxcvbn: realistic password strength estimation

#27
> One in nine people had a password in this top 500 list. These passwords include some real stumpers: password1, compaq, 7777777, merlin, rosebud.

Looks unbelievable at first. How could people be so stupid?

But I use such passwords all the time. I use a variety of websites where I have no need or desire for security. Want to post burrito reviews on burritophile.com as me? I picked something simple and easy to guess, a couple hours and you'll be going to town! (Just promise not to badmouth the Cosmic Cantina.)

My bank accounts? Oops, didn't use the same password.

Re: Zxcvbn: realistic password strength estimation

#28
I'm surprised to see that "correct horse battery staple" type pass-phrases really have to be quite long to score well, but that even comically short email addresses ("dlk3@mit.edu") score very highly. In fact, it looks like my ever-so-clever words-and-numbers web passwords ("Happy314Day") are all terrible, but all my email addresses all make maximum strength 4-point passwords.

I wonder if that's because email addresses are really hard to crack or if it's because the rules of this scoring system weren't designed to account for such a practice. Not a practice of using your real email address as a password, but the practice of using a fictional email address as a password.

Re: Zxcvbn: realistic password strength estimation

#29
post #2

> Bank of America doesn’t allow passwords over 20 characters, disallowing correcthorsebatterystaple. Passwords can contain some symbols, but not & or !, disallowing the other two passwords Can anyone elaborate why "&" or "!" wouldn't be allowed?

This may not be their reason, but I used to have a password with @ in it. Then I went to Germany and discovered the keyboards there didn't have @ on them. That was a fun time.

Re: Zxcvbn: realistic password strength estimation

#30
I feel like this is a stupid question, but what is wrong with having your password be something like "p4ssw0rd"? eg: a dictionary word where a few of the letters are switched for numbers, and maybe even a symbol at the end ("p4ssw0rd$") are these terrible passwords for some reason?
Post reply on HN