What do you mean password strength does not rely on length?
A longer password is MANY MANY MANY more times more secure than a complex one.
Microsoft has come in for a bit of stick in security circles for only allowing a 16-character password for sign-ups to Outlook.com, Redmond's newly launched Gmail rival. The service – which has already attracted more than a million sign-ups – has a maximum password length of 16 characters, the same as Hotmail.com and Windows …
What do you mean password strength does not rely on length?
A longer password is MANY MANY MANY more times more secure than a complex one.
An accessible open door policy.
Over a certain length people are far more likely to choose well known phrases or sayings, which drastically reduced password strength.
Which is the same mistake as using submarine1 as a password and being surprised it gets cracked in seconds.
"What do you mean password strength does not rely on length?"
Who said that? The article says password strength is more important than length alone, but also acknowledges that length is a factor in working out strength.
But no, 1234567890 isn't many many many more times secure than, say D¬s£_"
I got a spam email yesterday in my new outlook.com email inbox - it said...
"Worried, embarrassed, ashamed of the length of your password? Your password length fails to impress her? Feeling inadequate next to that fat nerdy dude in the IT office?....." etc
Then it went on trying to flog me "herbal password extenders!"
"The length of a password is less important than its strength, which depends on whether the login credential uses a mix of letter, numbers and non-alphanumeric characters (good) or words that might be found in a dictionary (terrible)"
The length of the password is in fact much, much more important to its strength than whether it uses non-alphanumeric characters and such like. See for example http://xkcd.com/936/.
It's pretty easy to see why length is so much more important than the characters you choose -- the number of possible passwords is exponential in the length of the password, but only polynomial in the size of the alphabet you're drawing from.
Maybe worth a read
Check out Steve Gibson's site also for some interesting insights about length versus complexity in passwords'
Or if you get a failed login for a particular e-mail address, simple deny all logins from that source IP for say, five seconds. Hardly a great inconvience to a genuine user making a typo on the password, but makes a remote "dictionary attack" (where the dictionary including all combinations of upper, lower case and digits) of even an eight-character password unfeasible.
Granted, if someone gets hold of the underlying password database, and so can circumvent the connection and time restrictions imposed when connecting remotely, then the shorter passwords are now much weaker than longer ones.
<quote src=Graham 24>[...]simple deny all logins from that source IP for say, five seconds. Hardly a great inconvience to a genuine user making a typo on the password, but makes a remote "dictionary attack" (where the dictionary including all combinations of upper, lower case and digits) of even an eight-character password unfeasible.[...]</quote>
these days it's a lot easier to do DISTRIBUTED dictionary attacks or port/vulnerability scans, denying logins from a particular ip address or address range is meaningless.
It's better to deny logins globally to that account for x seconds/minutes and after that to add a mandatory captcha to the login for the next few hours. I've even seen servers that always ask for captcha on logins (i configure mine this way too.).
"denying logins from a particular ip address or address range is meaningless."
It's there to preveny denial of service attacks against a single account.
"It's better to deny logins globally to that account for x seconds/minutes ".
If you do that, all I have to do is to log in as you with an incorrect password every few seconds, and you can never access your account. If you limit the lock out to the IP addresses that originated the failed login, the legitimate user can still get access.
"If you limit the lock out to the IP addresses that originated the failed login, the legitimate user can still get access."
or, you could do it the other way round: deny login attempts from any IP that has not previously successfully logged in to that account.
Either way you need to store _some_ IP addresses, the list of previously-successful IPs is likely to be much shorter than the list of DDOSing failed login sources.
"or, you could do it the other way round: deny login attempts from any IP that has not previously successfully logged in to that account."
I don't see how that'd work, the vast majority of users are likely to have a dynamic IP.
If the password is hashed and the size of the hash is (inevitably) much less than the typical size of the plaintext, then what? Do length or alphabet matter much at all?
Still, it's good to see Graham Clueless is still constructively occupied.
Hashes are a fixed length, independent of the input length, but a property of the hash itself. Placing a maximum length of the password might be a sign that they are storing the unhashed password in a fixed length DB string…
You obviously have no idea how hashing works if you think that a resulting hash being shorter than a very long pasword has any affect.
Might be worth doing some research
If the hash is shorter than the passwords, does it not imply that more than one password must have the same hash? And therefore that one need only find A working password and not THE original password? Not my field, so please enlighten me if I'm missing something.
To all: I think my math is OK here, but pls forgive me. I didn't use billion, as the meaning changes depending what side of the Atlantic you're on.
AC: I don't think you understand just how large a 128-bit number is, let alone a 256-bit number. 128 bits works out to around 3.40 × 10^38 different numbers.
Humor me here: Fit 3 x 10^11 (three hundred thousand million) hashes in a cubic millimetre...
A desktop HDD has an outside volume of 386,022 mm^3. At the same storage density as above, the HDD would have to be able to store 115,806,600,000,000,000 128-bit hashes or 1,852,905,600,000,000,000 bytes (1.9 million petabytes - 1.9 zettabytes) of data to match the storage density of that cubic mm above.
To visualize just how much data that is, think how big a pile nearly two million million 1TB drives would be. The annual HDD production of any sized-storage by the three largest manufacturers is 200M - so that'd be 10,000 years' production.
Last year, IBM announced that it is building a 120 PB HDD data repository - an array of 200,000 HDDs. That 1.8ZB HDD would represent 15,834 of IBM's arrays.
The volume of the Earth is roughly 1.097 x 10^27 mm^3. That's a thousand million million million million.
A planet-Earth-sized pile of 1.8ZB HDDs would be needed just to store all possible 128-bit hashes. (Seagate expects to use HAMR to produce 60 TB+ 3.5" hard drives within the next ten years - you'd still need 31,666 of 'em for ONE 1.9 ZB HDD.)
At current rates of manufacturing, you would need every HDD produced for 2.6 x 10^21 years just to store all possible 128-bit hashes. That's 1.8 x 10^11 times the age of the universe...
Oh, it gets worse, AC.
To store all possible 256-bit hashes, you would need 3.40 × 10^38 Earth-size piles of 1.9 ZB HDDs.
THAT, my friend, is sufficiently large haystack to hide a needle in.
Password hashing IS good practice. Best practice is salted hashing, with individual, random salts (assuming the salts aren't stored with the hashes) and a slow, or a memory-intensive hashing algorithm.
The one who needs to get a clue is you.
You're correct, but the security added by storing hashes rather than the password itself far outweighs the risks associated with hashing collisions.
Who? By not effectively identifying whom you are addressing, you're the one looking a bit clueless.
"I don't think you understand just how large a 128-bit number is"
I do understand that thank you, it's eight times wider than the 16bit numbers I grew up with, but I need some help understanding why anyone would think it's relevant in the context of a "discussion" re hashed passwords.
Yes, in hashes this is called a collision. When two or more plaintext items result in the same ciphertext (hash). The goal of hashes is usually not to eliminate all collisions (because it is impossible), but rather to make them as difficult as possible to generate and figure out without brute forcing through every single possible combination.
Or you could just click the "in reply to" button and find out, oh clueless one.
Alternatively it's fairly easy to work in out given the content of my message.
Outlook.com fails on a lot of important features besides password length.
Two factor authentication and IMAP are two very big ones. The problem with MS is they have a very strong culture of not invented here. For example, the outlook.com team recently had an AMA (ask me anything) on reddit and the constantly repeated question of "why don't you support IMAP, we want IMAP" was repeatedly responded with a cookie cutter meaningless response typically with "we support exchange active sync" much to the derision and face palming of redditors.
MS outlook.com simply cannot compete with gmail, they're out of touch with what people actually want versus what they think people should use/have.
I signed up for an account but was disappointed with both lack of IMAP and mobile support. Every email provider I use has a mobile webpage for speedy access but somehow outlook's doesn't work properly. Try m.outlook.com and it will initially open a mobile-looking outlook site but quickly re-direct you to the full website.
outlook is noticeably slower than gmail. you can see it refreshing the page dozens of times going to bay 002 bay 056 bay 089 for fucks sake just load my email up
I use easily remembered passphrases and these are parsed by a little (very well protected -only root readable) C program that swaps letters around, adds fixed characters, pads, adds different numbers to some characters etc. so that a simple passphrase like "Ballmer is a bum" comes out as (something) like :-
Just copy/paste. Anyone see a problem ?.
This is only for the really important ones such as finance or SSH where I think it's worth putting in a little effort. Even if someone gets local access to the computer and knows about my system they'd still have to know the passphrases ( I don't use MYBanksPassword etc. !)
Yes longer passwords are most certainly more secure but the geeks always overlook the user factor & they really believe people are going to use more characters than they have in their own name.
Its never going to happen that non-professional computer users use security best practices. NEVER going to happen.
The big rub is that major providers of software & hardware try to implement security for "the masses" but the loud voices of IT folks online scream & cry privacy issues so loud they push the providers into a half-cocked system. So thanks Sophos I guess. You've just provided another avenue for biometrics asshats to get involved.
and my users revolted. Smug pricks aside, what am I supposed to do about this? Fire my users? -- including the ones who sign off on my paychecks?
The length of a password is less important than its strength
It's all about entropy bits and the statement alone delivers misinformation. Using 2 letters from a-z allows for more bits than the entire ASCII set altogether.
Strength is an exponential function of a password's length.
*Even if you throw together 5 random unrelated dictionary words, you still have ~ 200,000^5 possibilities.
An 8 letter password using a-zA-Z and punctuation is ~ 64^8 possibilities.
It would take 1136868377216 times as long to crack the password based on dictionary words using a brute force attack.
Clearly long passwords using just dictionary words are vastly more memorable and secure than 8 letter passwords composed of random characters.
The statement is at best misleading, though I'd go with just plain wrong.
*Assuming 200,000 dictionary words, OED estimates a quarter of a million not including inflections
"Clearly long passwords using just dictionary words are vastly more memorable and secure than 8 letter passwords composed of random characters."
Might be true but most people don't know what many of the 200k words in the English dictionary mean. Most people have a working vocabulary of about 5000 words. I'm pretty much prepared to bet that if you asked most people for 5 random words you would get 5000^5 ~= 10^18 bits of entropy at most. So I reckon you're out by a factor of 100 million or so in you estimate.
You're still better off with this than 8 characters though.
Ok, I never stated 'generated by a human', I was assuming a computer would generate both the random words and password, because humans are frankly shite when it comes to generating random sequences of anything.
Even 5000^5 is more than 64^8. That's ignoring the fact that a normal human vocabulary is *50,000 words (and we're still not including inflections). So your argument fails even on it's own rather suspect numbers.
*source: BBC http://news.bbc.co.uk/2/hi/uk_news/magazine/8013859.stm
verified equine accumulator fastening
Wow, I can see you didn't read my post before hitting the downvote button. It actually agrees that 5000^5 is still better than 64^8. It's just a note of caution that the xkcd 'correct horse battery staple' entropy is often overestimated. I'd normally be interested to know why you think my 'argument fails even on it's own rather suspect numbers' but the fact you couldn't even read and comprehend this short post tells me all I need to know.
I'm kinda curious how you reached the conclusion "You are still better off with 8 characters though.".
It's funny this exact issue is how come I one day went into an interview for a junior developer role at a medium sized firm in Norwich and came out as their Head of Security.
They were using an aging in-house order system which required all employees change their password every 90 days. The problem was there were no proper constraints on password length or complexity and they had discovered employees were using twatish passwords like "123" and even " " (a single space!). They wanted me to join their developer team in a project to add proper password constraints to the system. I looked them in the eye and said something like "cancel your expensive security project and make me head of security, I can fix this for you without hassle or expense". Needless to say they gave me the keys to the castle that very afternoon.
My trick was to track the 90-day period before which an employees password expired. The night before a password expired I would remove that employee's monitor and lock it in the security room. The next day they would have to come to me for their monitor, at which point I would sit them down and oversee them entering their new password to make sure it met constraints.
I even introduced my own password complexity scheme. To foil hackers, employees were made to fire up character map and switch to the wingding character set. They would then choose 8 symbols* and copy paste them into the new password field using the mouse. This not only foiled keyloggers but I discovered that the characters get "converted" after they are pasted into normal characters, thus even if hackers could see the new password field they would just see something like "hgfiofkg", but not the actual wingding characters behind it.
*The symbols they choose had to be authorized by myself - which was easy as I, or a member of the security team (I say "security team" but the only other member was the bosses nephew who was more of a temp and had no idea about security) was sitting behind them watching the whole process. I disallowed simple symbols, especially arrow symbols which could potentially be easily rotated by cracking software. Although as I told my future boss in the interview, all the password crackers out mainly just try different combinations of normal letters and numbers so the last thing they'd expect is wingding.
Ermm. and you seeing all the passwords isn't a security issue?
What a ripping yarn.
Two out of ten. It shouldn't be obvious you're full of shit by the end of the second paragraph. Troll harder.
Why didn't you just configure the password change program to require a complex password?
" This not only foiled keyloggers but I discovered that the characters get "converted""
"Head of Security" discovers that Wingdings is just a bloody font... In other news, he flies to the moon powered only by his own sense of illusion.
Strictly speaking, you give a guy a torch and a nice blue uniform and have him guard a small lock-up in Norwich, he's "head of security"...
But realistically I think we're being trolled good and proper
Cool story, bro.