2 ms·

Note the part where the example says "squash:club", not "n!mGgl342r0nin" Password guessing and cracking is part of my job. GP is right: the advice is absolutel

by Aachen 4y ago

Note the part where the example says "squash:club", not "n!mGgl342r0nin" Password guessing and cracking is part of my job. GP is right: the advice is absolutely terrible. Your example looks good but the secret sauce is the way by which you create it. Maybe it's just leetspeak for something a million fans know, in which case it would be in my dictionary by virtue of downloading Wikipedia and other cracked password lists and the leetspeakify rules will find it in a matter of hours or days for a typical leaked hash (this looks like a domain admin password we might find on a workstation they logged into). Eyeballing mGgl3etc., it doesn't look like something you'd find in anyone else's password, which makes it unpredictable, which makes my job hard and your account safe. But you can't determine a password's strength from the generator's output (only if it's terrible) so idk.

jmholla 4y ago
How do you usually direct people to generate passwords they'll need to remember?
- teddyh 4y ago
  https://xkcd.com/936/ https://xkcd.com/936/
  - joe_guy 4y ago
    That's really good advice if you use the same password for everything. It becomes untenable with the, what, hundred+ websites I have a login for, each with their own password.
    - teddyh 4y ago
      Then you need a password manager. OTOH, people in the old days used to memorize a lot of phone numbers, so remembering things is not as hard as you might think.
      - deleted 4y ago
        [deleted]
- Aachen 4y ago
  Password manager. The password for which you're best off randomly generating and memorizing if you're able (one of my grandparents can't remember a 4-digit banking PIN so that's a sticky note on the back of her card... do what one can). Also memorize, if possible, a few other important things like your bank password, or rely on 2FA for that, e.g.: we have a system where you log in with a reader for your card itself, so your password being stolen and your chip+pin being stolen is a risk I accept. If someone is after me specifically enough to get physical things out of my pocket, I'm not confident about resisting a rubber hose for that password / they can also install a keylogger. For generating a password, it just needs enough entropy if you calculate log(pool^elements)/log(2): - pick 6 actually random words (like in the xkcd) from a 7776-word dictionary like diceware, or some other combination that gets you at least 72 bits of randomness (so here it is log(7776^6)/log(2)), - or use a much shorter but slightly harder to remember set of random characters (a-z, A-Z, 0-9 would need 13 characters. If you don't want to bother with shift at all but include a few (10) symbols that don't need shift, add one character. Depending on the password manager, it would strengthen with a KDF, but that depends on details and remembering just a handful of 72+ bits of randomness should be attainable for most people if they use it regularly (at least once or twice a month after the memorization phase). I should really find a canonical source for this so I don't have to write this up every time. Not sure if Schneier has this somewhere but I looked at e.g. the Wikipedia on password strength (a source people would trust) and it's less explicit and also contained a pretty bad mistake for more than a year not so long ago...
Zurrrrr 4y ago
> Note the part where the example says "squash:club", not "n!mGgl342r0nin" Sure, the example I gave was more complex, but I was specifically referring to the "We recommend choosing a word or phrase that means something to you, and then adding one or two numbers or symbols, like "!" or "+"." being terrible advice. It's not great advice, but they are on the right track. > Password guessing and cracking is part of my job Same here. > GP is right: the advice is absolutely terrible. It was just worded badly. > Maybe it's just leetspeak for something a million fans know, in which case it would be in my dictionary by virtue of downloading Wikipedia and other cracked password lists and the leetspeakify rules will find it in a matter of hours or days for a typical leaked hash (this looks like a domain admin password we might find on a workstation they logged into). Sure, there are tons of domain specific dictionaries, but that's really more useful for people that are targeting an individual and know something about them, or are just going to go through every dictionary they can. Most attackers are not doing that. And besides, it's not about ensuring the password can never be cracked, that's not a great goal considering the compromise it would take - the goal is to delay brute forcing enough so that you can change passwords after you have an alert that a site has been breached.

by Aachen 4y ago

jmholla 4y ago

How do you usually direct people to generate passwords they'll need to remember?

teddyh 4y ago
https://xkcd.com/936/ https://xkcd.com/936/
- joe_guy 4y ago
  That's really good advice if you use the same password for everything. It becomes untenable with the, what, hundred+ websites I have a login for, each with their own password.
  - teddyh 4y ago
    Then you need a password manager. OTOH, people in the old days used to memorize a lot of phone numbers, so remembering things is not as hard as you might think.
    - deleted 4y ago
      [deleted]
Aachen 4y ago
Password manager. The password for which you're best off randomly generating and memorizing if you're able (one of my grandparents can't remember a 4-digit banking PIN so that's a sticky note on the back of her card... do what one can). Also memorize, if possible, a few other important things like your bank password, or rely on 2FA for that, e.g.: we have a system where you log in with a reader for your card itself, so your password being stolen and your chip+pin being stolen is a risk I accept. If someone is after me specifically enough to get physical things out of my pocket, I'm not confident about resisting a rubber hose for that password / they can also install a keylogger. For generating a password, it just needs enough entropy if you calculate log(pool^elements)/log(2): - pick 6 actually random words (like in the xkcd) from a 7776-word dictionary like diceware, or some other combination that gets you at least 72 bits of randomness (so here it is log(7776^6)/log(2)), - or use a much shorter but slightly harder to remember set of random characters (a-z, A-Z, 0-9 would need 13 characters. If you don't want to bother with shift at all but include a few (10) symbols that don't need shift, add one character. Depending on the password manager, it would strengthen with a KDF, but that depends on details and remembering just a handful of 72+ bits of randomness should be attainable for most people if they use it regularly (at least once or twice a month after the memorization phase). I should really find a canonical source for this so I don't have to write this up every time. Not sure if Schneier has this somewhere but I looked at e.g. the Wikipedia on password strength (a source people would trust) and it's less explicit and also contained a pretty bad mistake for more than a year not so long ago...

Zurrrrr 4y ago

> Note the part where the example says "squash:club", not "n!mGgl342r0nin" Sure, the example I gave was more complex, but I was specifically referring to the "We recommend choosing a word or phrase that means something to you, and then adding one or two numbers or symbols, like "!" or "+"." being terrible advice. It's not great advice, but they are on the right track. > Password guessing and cracking is part of my job Same here. > GP is right: the advice is absolutely terrible. It was just worded badly. > Maybe it's just leetspeak for something a million fans know, in which case it would be in my dictionary by virtue of downloading Wikipedia and other cracked password lists and the leetspeakify rules will find it in a matter of hours or days for a typical leaked hash (this looks like a domain admin password we might find on a workstation they logged into). Sure, there are tons of domain specific dictionaries, but that's really more useful for people that are targeting an individual and know something about them, or are just going to go through every dictionary they can. Most attackers are not doing that. And besides, it's not about ensuring the password can never be cracked, that's not a great goal considering the compromise it would take - the goal is to delay brute forcing enough so that you can change passwords after you have an alert that a site has been breached.