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Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

paul.reviews

21–30 of 87 posts

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#21
post #5

The ONE thing stopping me from using a password manager is fear that I'll lose the master password. How do I get over this fear? Another thing is for example Chrome's built in password manager. If I make a bunch of accounts with these passwords, do I NEED Chrome to ever be able to log in to these accounts?

If you're not using a password manager now, that implies you're already remembering at least one password. Using it on a regular basis is a good way to keep it in your head.

You can setup your password manager authorization to expire periodically (eg, every 30 days) as well as on reboot. With LastPass (probably others) you can also mark certain sites as 'high security' and require entering your master password again. I do this with a small handful of sites, including my bank and domain registrar. I typically log into my bank once or twice a month.

I very rarely reboot my devices (sleep + locked with a different password I have memorized and type in) so I don't get prompted for it that much otherwise, but enough that I have it memorized.

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#22

What I don't understand is the math. Author makes the claim that using 3 words changes the combinatorics from 62^12 (62 characters, in 12 positions) to 20,000^3 (20k words, in 3 positions) but a hashing algorithm doesn't work with words, it works with characters, so if the words are 4 characters each, you've still got 12 characters to fill. Since an attacker doesn't know that you've not used symbols or numbers, they…

Exactly. The attacker would have to try a word-based attack to benefit from the ~7 hour time-to-crack.

So I disagree with the article's advice: "Don't use words in passwords. Ever." Yes, you should use caution when using words in a password, but even if you use a password manager, a 5- or 6-word diceware password is ideal. Even better if you stick on a 4-digit numeric "salt" to your diceware passwords.

But yes, I do agree that a 3-word password is too short (~33 bits of entropy[1]). It should be at least 5 words (~55 bits). And you really need at least 6 words (~66 bits, obviously) for a master password.

1. Using EFF's user-friendly, ~1200 word list for diceware.

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#23

What I don't understand is the math. Author makes the claim that using 3 words changes the combinatorics from 62^12 (62 characters, in 12 positions) to 20,000^3 (20k words, in 3 positions) but a hashing algorithm doesn't work with words, it works with characters, so if the words are 4 characters each, you've still got 12 characters to fill. Since an attacker doesn't know that you've not used symbols or numbers, they…

I haven't had the time to read the full article, however I think I might have an answer to your question. The entropy computes the strength of the algorithm used to generate passwords, not the strength of the password itself. So basically, you are getting the strength of the password if the attacker knows the algorithm.

I couldn't find a better source than this stackexchange thread : https://security.stackexchange.com/questions/167235/how-does...

Hope it helps

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#24

I feel like the real take-away from this article is that MD5 is broken, something we've all known for ages. An application using a memory-hard algorithm like bcrypt would yield the same results, but without the hassle of retraining all users to use longer passwords.

Yup, also no mention of salting the passwords.

The 200 billion md5 hashes per second figure they use matches up nicely with this 8x GTX 1080 system: https://gist.github.com/epixoip/a83d38f412b4737e99bbef804a27... which cracks bcrypt (at a weak security factor) two million times slower.

So, that same system would crack a 3 word password at this weak bcrypt setting in about 3 years, and a 4 word password in 50 thousand years.

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#25
post #5

The ONE thing stopping me from using a password manager is fear that I'll lose the master password. How do I get over this fear? Another thing is for example Chrome's built in password manager. If I make a bunch of accounts with these passwords, do I NEED Chrome to ever be able to log in to these accounts?

Most password managers have an emergency kit, where you can print your master password and other info, and put it somewhere like a safe, bank vault, etc

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#26
post #5

The ONE thing stopping me from using a password manager is fear that I'll lose the master password. How do I get over this fear? Another thing is for example Chrome's built in password manager. If I make a bunch of accounts with these passwords, do I NEED Chrome to ever be able to log in to these accounts?

To keep track of your master password, just write it down and put it in your wallet/purse. We're used to and experienced with securing physical objects, and while it still offers an avenue to expose all your passwords, it requires a lot of extra work to do so. Basically, storing your master password physically only really vulnerable to highly targeted attacks.

I would put it somewhere more secure than wallet/purse, unless you are forgetting your master password daily. I put mine in a place similar to a hidden folder in a filing cabinet. I haven't forgotten my master password yet, but I know that it's there if I need it.

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#27
post #5

The ONE thing stopping me from using a password manager is fear that I'll lose the master password. How do I get over this fear? Another thing is for example Chrome's built in password manager. If I make a bunch of accounts with these passwords, do I NEED Chrome to ever be able to log in to these accounts?

Write it down on paper, put it in an envelope, and leave it in your home, preferably in a small fire resistant lockbox that you keep other important documents in. If your home isn't secure enough for this purpose due to roommates or other issues, ask a trusted friend, parent or relative to hold onto it and your other important documents on your behalf. If your situation makes putting it in someone else's hands a prob…

Not a safety deposit box at the bank?

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#29
Novice in the area, so grain of salt (and if you can correct me where I'm wrong, that'd be great. All for learning):

1) I don't think the base changes nor the exponent deviates from the character approach (in reference to the 20,000, 40,000, and 171,000 base stated). If we're in a system that allows all uppercase letters, all lower case letters, all special characters, and all numbers, then the base is the sum of those: regardless if my password is purplepenguinparade because you don't know that I've artificially set parameters for my password within the existing parameters. It could be argued you could try all permutations of lowercase characters first (base 26) but then how do you know to go to 26^19 before adding more to the base?

1a) if the hashed passwords give away tells as to what the decoded password is like (in this case 3 words lowercase), that'd seem like a concern about the encryption moreso than the password.

2) The 20,000 and 40,000 part seems like a meaningless piece of trivia. What if one of the words I want to use doesn't fall in your 20,000-40,000 word store? You're never going to crack my password. Better go the full 171,000 or whatever it was and hope I don't slip an extra character of the numeric, special character, upper/lower case variety.

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While I do personally use a password manager, it isn't perfect for me either (requires loading 1Password 2x on Windows 10 for me because the first attempt does nothing, but loads on second try). I do hope more OS creators do like Apple did to better tie in with password managers and that may help alleviate some of it). So I don't see my parents or grandparents, for example, using one.

That said, for the rank and file folks that are taking their security advice from the government and police departments, I think pushing for various words in sequence is much better advice than "8 characters in length because it takes longer to guess than 6 characters" or whatever it is that people predominantly operate under and usually ties back to something about themselves that someone with some familiarity about them could guess (if I recall, this is what happened to Sarah Palin when she was hacked shortly after being McCain's VP nominee).

Re: Passwords: Using 3 Random Words Is a Really Bad Idea (2017)

#30
post #5

The ONE thing stopping me from using a password manager is fear that I'll lose the master password. How do I get over this fear? Another thing is for example Chrome's built in password manager. If I make a bunch of accounts with these passwords, do I NEED Chrome to ever be able to log in to these accounts?

Most services have a mechanism through which you can reset your password, usually email. Losing access to your password store isn't the end of the world.
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