4 ms·

You ask a yes/no question, someone says "yes", you say "so what?". You should have just started there. "So what if someone gets my email and password for whatev

You ask a yes/no question, someone says "yes", you say "so what?". You should have just started there. "So what if someone gets my email and password for whatever website?" So in your very specific contrived scenario that a user is using weak passwords but never reusing them, yes they are fine provided the site with the leaked account data realizes this and makes you reset your password. But we already know that in reality most people reuse weak passwords. If your reused password was a passphrase that wasn't in the dictionary and couldn't be brute forced in a reasonable time, then you would be fine.

coldpie 2y ago
My point with this thread is that if you're focusing on entropy, you're wasting your time. It doesn't matter beyond some threshold, which I argue is quite low. It doesn't matter if it takes 500 years or 5000 years to crack your password, no one's doing it so long as it's beyond (say) 3 months of CPU time. It would be better to focus on easy and unique, than to focus on entropy.
- fkyoureadthedoc 2y ago
  Yes I agree that the passwords should be unique, easy to type manually when you have the need, and some minimum threshold of entropy is nice to have. I have no idea what that minimum should be though. Aren't passwords cracked with GPU? I admittedly have no clue about this, but it sounds right to me lol. Assuming they are, a 4090 can probably guess a hell of a lot of passwords per second. I've had the same generated strong Reddit password for like 15 years, what are GPUs going to look like in the next 15? The last time I had to implement password login for something we just followed NIST guidelines and called it a day.
- freedomben 2y ago
  It depends on what "easy" means to you, but assuming some minimum level of "easy" I would agree. I typically encourage people to think in pass phrases instead of pass words, like the xkcd[1] except throw some personal variances in there. A substituted misspelling, a fake word, intersperse some meaningful numbers, (basically anything to make the standard dictionary attack algorithms fail at generating your password). [1]: https://xkcd.com/936/ https://xkcd.com/936/
- joshka 2y ago
  The measure of uniqueness is effectively entropy (entropy = log base 2 of the number of possible passwords). Ease of use is just unnecessary (for entropy purposes) padding on top of that (constraints on symbol sets, order, etc). The necessary threshold is entirely dependent on your threat model, combined with the risks that your use cases are exposed to when using the password. Your point that using entropy rich passwords is foolish, is incorrect most of the time, and even if it weren't people's general understanding of where specifically to draw that line is generally significantly underestimated as a collective. The evidence of this is the amount of data breach information available, and the actual attacks which are available using this information. Service breaches happen where the password database is insufficiently secured, and that often correlates strongly with insufficient protection of the password hashes. This means that low entropy passwords can be cracked and used for a period of time before the data breach is discovered. Entropy (and MFA) are the only protections against that. 56 DES was cracked in a day in 1999. Your passwords should definitely have more entropy than that. Probably around 80 bits is enough (about 16 alphanumeric characters or so). Your much lower threshold on entropy is insufficient for pretty much any reasonable threat model except public access.

coldpie 2y ago

My point with this thread is that if you're focusing on entropy, you're wasting your time. It doesn't matter beyond some threshold, which I argue is quite low. It doesn't matter if it takes 500 years or 5000 years to crack your password, no one's doing it so long as it's beyond (say) 3 months of CPU time. It would be better to focus on easy and unique, than to focus on entropy.

fkyoureadthedoc 2y ago
Yes I agree that the passwords should be unique, easy to type manually when you have the need, and some minimum threshold of entropy is nice to have. I have no idea what that minimum should be though. Aren't passwords cracked with GPU? I admittedly have no clue about this, but it sounds right to me lol. Assuming they are, a 4090 can probably guess a hell of a lot of passwords per second. I've had the same generated strong Reddit password for like 15 years, what are GPUs going to look like in the next 15? The last time I had to implement password login for something we just followed NIST guidelines and called it a day.
freedomben 2y ago
It depends on what "easy" means to you, but assuming some minimum level of "easy" I would agree. I typically encourage people to think in pass phrases instead of pass words, like the xkcd[1] except throw some personal variances in there. A substituted misspelling, a fake word, intersperse some meaningful numbers, (basically anything to make the standard dictionary attack algorithms fail at generating your password). [1]: https://xkcd.com/936/ https://xkcd.com/936/
joshka 2y ago
The measure of uniqueness is effectively entropy (entropy = log base 2 of the number of possible passwords). Ease of use is just unnecessary (for entropy purposes) padding on top of that (constraints on symbol sets, order, etc). The necessary threshold is entirely dependent on your threat model, combined with the risks that your use cases are exposed to when using the password. Your point that using entropy rich passwords is foolish, is incorrect most of the time, and even if it weren't people's general understanding of where specifically to draw that line is generally significantly underestimated as a collective. The evidence of this is the amount of data breach information available, and the actual attacks which are available using this information. Service breaches happen where the password database is insufficiently secured, and that often correlates strongly with insufficient protection of the password hashes. This means that low entropy passwords can be cracked and used for a period of time before the data breach is discovered. Entropy (and MFA) are the only protections against that. 56 DES was cracked in a day in 1999. Your passwords should definitely have more entropy than that. Probably around 80 bits is enough (about 16 alphanumeric characters or so). Your much lower threshold on entropy is insufficient for pretty much any reasonable threat model except public access.