Live data from Hacker News

49% of workers, forced to change passwords, reuse same one with minor change

grahamcluley.com

291–300 of 316 posts

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#291

This should not be a surprise, as this supports the NIST's revised recommendations (from June 2017!) that passwords should not expire [0], because it actually leads to less-secure passwords for this exact reason. Furthermore, many corporate systems do not integrate well with password managers, such as when first logging in to your system in the morning. This means that the password is likely to be one of the few that…

My argument for password expiry (300 days here) is my users have complained they can't keep using the password they use everywhere else.

My workplace does this (every month). Everyone just appends a number. Either the current month, or one they write on a post-it on their desk.

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#292
post #194

Earlier quoted context omitted.

Which is why at a previous employer, everyone just stuffed all of it in a spreadsheet, with expiry dates, and last logged in times.

That actually sounds pretty secure, if the computer had a reasonable password and FDE you've just implemented a hacky password manager. Even without FDE you're better than anyone who writes it down on a sticky or uses something trivial. Unless they're using Excel functions to generate password{n++} . That'd be clever and yet horrid at the same time.

I used a little php script to do the password generation, and yes we did use FDE

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#294
post #292

Earlier quoted context omitted.

That actually sounds pretty secure, if the computer had a reasonable password and FDE you've just implemented a hacky password manager. Even without FDE you're better than anyone who writes it down on a sticky or uses something trivial. Unless they're using Excel functions to generate password{n++} . That'd be clever and yet horrid at the same time.

I used a little php script to do the password generation, and yes we did use FDE

If the script is accessible to other people I suppose you have to worry about it being hacked, especially if you let php get out of date or take input in say password length?

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#295
post #285

Earlier quoted context omitted.

There's absolutely no way a five word password is better than 32 random characters. Two plain old random words, the entropy of that is less than 16 bits each, but we'll round up. One of the biggest cities in the US is probably even less useful, but let's credit it for 16 bits. And let's rate Zaphod Beeblebrox as one-in-a-million for entropy purposes. That's 68 bits. It's somewhere between 11 and 12 random alphanumeri…

> There's absolutely no way a five word password is better than 32 random characters. That assumes the attacker knows it's a five word password, and that there are no misspellings, and that these are specifically English dictionary words in dictionary form, how you're capitalizing it, and whether or not you snuck a number or an exclamation mark in the middle. Might as well know your password at this point.. raivoissa…

Guessing that it's English words is no harder than guessing that it's random uppercase/lowercase/numbers. So that part cancels out. Realistically you'd try all simple patterns in order of complexity. This makes cracking slower than knowing the pattern up front, but the password is already getting exponentially harder to crack every time it gets longer. The small factor of trying different simple patterns pales in comparison.

The attacker doesn't need to know how many words. They would try 1, then 2, then 3, etc.

Capitalization and tiny modifications are only worth a few bits. They can't get you anywhere near the quality of 32 random alphanumerics.

Your password example is a lot stronger. But even then I don't know if it's better than a full 32 random characters. That would mean every two characters in your password have more randomness than a completely random character with no patterns. That might be true.

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#296

Earlier quoted context omitted.

I ran a few tests with zxcvbn using five words (only nouns and verbs) and it estimates the complexity at roughly the same as that of a 32 random alphanumeric character password with capitals. Is zxcvbn wrong?

It is correct if I don't know anything about you. Once I know you use a sentence, I would use a dictionary to attack your password

Even knowing nothing, any sane password cracker would attempt five letter sentences long long before they even reached 30 character alphanumerics. And 30 characters is itself more than a thousand times easier to crack than 32.

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#297
Reminds me of the first job of my career.

We had a 30-day password reset policy enforced by Active Directory group policy. I couldn't have told you what rules were required to get the system to accept the password, but it well beyond the default/typical AD policy[0]. To "enhance security", ours included a requirement that none of the prior 10-or-so passwords could be used, had a 12-character minimum[1] which IIRC, required also setting the "Store passwords using reversible encryption[2]". We allowed 30 bad logins, but a good login had to occur before lock-out or it required tech staff intervention.

We would have been better off having a non-resetting password policy with a reasonable minimum length. For the first 9 months of my career, I was top-tier end-user support[3]. It took about 2-months before I stopped asking people for passwords. 95% of the time, the password was "MonthNameYearNumber!!!!" with bangs filling in the rest, i.e. "March19991!!!!!!!!", or some variation. However, the frequency with which it was exactly that pattern was amazing. So that gave me 12 tries to get a password. I rarely locked out an account.

As is usually the case ... there's a law of unintended consequences. People will seek to reduce the friction to getting their job done and aren't great at assessing risk. In addition, the risk to an individual password is low. Even the result of a successful breach of a user's password is often not devastating to the individual who was attacked when that password is a LAN login (chances are you're not storing your own personal financial information on your work PC).

One of the odder unintended consequences -- figuring out the appropritae incantation to generate an acceptable password for the system was ... way more difficult than it should have been. I'm fairly certain one of our security tools was just broken. We had something that applied far more strict rules about password history than what AD could enforce, looking specifically for people using patterns, along with some other odd ones, like "you cannot repeat the same character", so "umbreLLa" was rejected. They, literally, reduced the number of possible passwords that a brute-force attack would require.

There was an interesting bug there -- we discovered that after the account was created, if only one password was in the password history, it would pretty much refuse to allow any password that didn't contain half of the characters, in the same place, as the prior password. Then, future required password resets would refuse all passwords that were similar to the previously rejected ones which were used on that account. However, if you used one of those rejected passwords on an account that hadn't had them rejected on that first reset, they would be allowed for that user.

I'm guessing they reversed a boolean somewhere (no similar past passwords) and that the security software stored a history of rejected passwords for future validation (no idea why this would be done, but then, no idea why it'd be illegal to duplicate characters), but security ditched all of those products when AD was upgraded and the tools stopped working. I know one of the reasons for the odd password rules were that we synced passwords to the Mainframe accounts, and they had a set of nonsensical rules that were very similar.

[0] If memory serves, default was 10 bad passwords before 1 hour lock-out, password had to have at least one number, one lower-case and one upper-case letter with an 8-character maximum and 90-day reset.

[1] I believe there's a study or two that indicates somewhere around 7-10 is typical for what a person can memorize easily. I've always wondered why. In my childhood, memorizing a 7-digit or 10-digit phone number for several people was something everyone did, so it's arguable that people my age have that ability out of necessity. I wonder what would be found if that were re-done, today, with people who are too young to remember days before speed-dial. Maybe it has been: https://abcnews.go.com/Technology/brain-memory-magic-number/...

[2] This sounds horrifying when thinking about passwords in today's terms, but storing as a password hash resulted in storing a Lan Manager Password hash which is very low quality (fairly certain this is moderately improved in later versions of AD but is still able to be enabled).

[3] I remember joking that we were helpdesk staff without phones; our "ticket system" was voicemail/e-mail. Basically, if the helpdesk couldn't solve it over the phone, we arrived at a cubicle, often with a screw-driver.

edit: bumped tab and accidentally hit "enter" for a newline ... submitting before I was done :(

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#298
post #285

Earlier quoted context omitted.

> There's absolutely no way a five word password is better than 32 random characters. That assumes the attacker knows it's a five word password, and that there are no misspellings, and that these are specifically English dictionary words in dictionary form, how you're capitalizing it, and whether or not you snuck a number or an exclamation mark in the middle. Might as well know your password at this point.. raivoissa…

Guessing that it's English words is no harder than guessing that it's random uppercase/lowercase/numbers. So that part cancels out. Realistically you'd try all simple patterns in order of complexity. This makes cracking slower than knowing the pattern up front, but the password is already getting exponentially harder to crack every time it gets longer. The small factor of trying different simple patterns pales in com…

> The small factor of trying different simple patterns pales in comparison.

I'm not sure I agree with that. There's an infinite number of simple patterns that one could construct, and guessing the right one from the space of all possible patterns could alone exhaust any bruteforce capability. The characters of a random password could be taken as constants that define a simple pattern according to some rule, so you can have as much entropy in the space of such patterns as you have in a randomly generated alphanumeric password; in a manner of speaking, the pattern is part of a password and by itself contributes to entropy (as long as we're talking about patterns with long enough outputs that different patterns don't have much overlap in what they spit out).

If the attacker doesn't have a huge library or eof simple patterns, then making an unbreachable passwords is very simple: just make up a new pattern, they probably won't guess it.

(Dang, now I'm tempted to make a game out of this: write a pattern generator, post a set of parameters in the public along with the md5 of the resulting pattern, and award some monies to the first person to figure it out.)

> The attacker doesn't need to know how many words. They would try 1, then 2, then 3, etc.

Sure. At what point would they exhaust their bruteforce capability or decide that they've probably got the wrong pattern and go for another one?

I hope the next pattern they choose isn't one to four random English dictionary words followed by the number of letters in the resulting phrase, expressed in binary using X for 1 and Y for 0!

> Capitalization and tiny modifications are only worth a few bits.

Five times a few bits quickly adds up though.

> Your password example is a lot stronger. But even then I don't know if it's better than a full 32 random characters. That would mean every two characters in your password have more randomness than a completely random character with no patterns. That might be true.

It's pretty hard to say since I made it up on the spot instead of randomly generating it after specifying a pattern, yeah.

But if you had just five words in different languages and you had to guess the language for each, that is quite a bit of entropy. Not enough to prevent any sort of brute force attack, but we're talking a few dozen bits at least. A quick google search shows that there are around 4000 human languages with at least 1000 speakers (https://www.infoplease.com/askeds/how-many-spoken-languages), that'd be 12 bits per word. You could guess it's got to be one of the most common 100 languages and you'd miss three languages that I used (Norwegian, Finnish, Esperanto), according to this list of top languages by native speakers: https://en.wikipedia.org/wiki/List_of_languages_by_number_of....

Of course not all words are unique across all languages, so a dictionary attack against my pattern could pick the wrong language for some word and still score the right dictionary entry.

Inflection, in the case of Finnish, proves interesting because there are ways to stack different endings and thus you can have hundreds or thousands of variations of a word, by the book. Slang and regional dialects only add to it.

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#299
post #298

Earlier quoted context omitted.

Guessing that it's English words is no harder than guessing that it's random uppercase/lowercase/numbers. So that part cancels out. Realistically you'd try all simple patterns in order of complexity. This makes cracking slower than knowing the pattern up front, but the password is already getting exponentially harder to crack every time it gets longer. The small factor of trying different simple patterns pales in com…

> The small factor of trying different simple patterns pales in comparison. I'm not sure I agree with that. There's an infinite number of simple patterns that one could construct, and guessing the right one from the space of all possible patterns could alone exhaust any bruteforce capability. The characters of a random password could be taken as constants that define a simple pattern according to some rule, so you ca…

> At what point would they exhaust their bruteforce capability or decide that they've probably got the wrong pattern and go for another one?

Go in increasing order of difficulty. Or estimated rarity based off of password dumps.

Something like: One character, two characters, one word, one word plus a character, one character plus a word, one modified word, three characters, etc.

"word" being a list of most common words in the united states, or something. Like you said, using many languages screws up dictionary attacks. But most passwords don't do that.

> I hope the next pattern they choose isn't one to four random English dictionary words followed by the number of letters in the resulting phrase, expressed in binary using X for 1 and Y for 0!

That would just be "four words plus five random characters".

Re: 49% of workers, forced to change passwords, reuse same one with minor change

#300
post #298

Earlier quoted context omitted.

> The small factor of trying different simple patterns pales in comparison. I'm not sure I agree with that. There's an infinite number of simple patterns that one could construct, and guessing the right one from the space of all possible patterns could alone exhaust any bruteforce capability. The characters of a random password could be taken as constants that define a simple pattern according to some rule, so you ca…

> At what point would they exhaust their bruteforce capability or decide that they've probably got the wrong pattern and go for another one? Go in increasing order of difficulty. Or estimated rarity based off of password dumps. Something like: One character, two characters, one word, one word plus a character, one character plus a word, one modified word, three characters, etc. "word" being a list of most common word…

> That would just be "four words plus five random characters".

Aye.. if you were going to pick the simplest (most bruteforceable) pattern first, you wouldn't want five random characters now, would you? I thought that's the whole point of this exercise :-) Of course I could decide to repeat that bit pattern four times and that adds no entropy if the pattern is assumed to be fixed, but then we get back to having the attacker try guess the right pattern.

Very often in these discussion people don't consider the pattern space at all as part of entropy and they only look at the entropy within the alphabet/words/variations after the pattern is fixed. I'm not sure that's right.

Post reply on HN