6.5 Million LinkedIn Password Hashes Leaked • Hacker News Board

Re: 6.5 Million LinkedIn Password Hashes Leaked

#391

Post by raverbashing » Wed, Jun 06, 2012, 6:29 PM UTC

pjscott wrote: post #366

raverbashing wrote: post #344

Earlier quoted context omitted.

I didn't do the math but it sounds right. But suppose tomorrow it takes 10ms. Also, tomorrow, available spaces will increase, so the likelihood of a space vs time tradeoff (even partial) increases WEP was considered "good enough" at first (even though it had obvious problems at first like key size), WAP was considered unbreakable at first, today it's feasible with cloud computing or GPUs. And then we'll be complainin…

The time bcrypt takes is configurable, so in the future you can adjust the amount of work per password -- this is literally a one-character change in your code -- and be alright again. Ditto for the rest of the decent password hashing schemes.

True, but you can't really bet on that

Sure, you can increase the work, but you'll still be limited by bcrypt size

Otherwise, you could just MD5 hash stuff X times and be done with it

Sure, bcrypt today is very safe, but I wouldn't be surprised if attacks are found today (even if they rely only on bruteforce)

And let's not forget implementation issues that may happen in specific bcrypt libraries

Re: 6.5 Million LinkedIn Password Hashes Leaked

#392

Post by royce » Wed, Jun 06, 2012, 6:30 PM UTC

jgrahamc wrote: post #170

Some observations on this file: 0. This is a file of SHA1 hashes of short strings (i.e. passwords). 1. There are 3,521,180 hashes that begin with 00000. I believe that these represent hashes that the hackers have already broken and they have marked them with 00000 to indicate that fact. Evidence for this is that the SHA1 hash of 'password' does not appear in the list, but the same hash with the first five characters…

A stock JtR 1.7.9-jumbo5, using the default rules, is finding quite a few of the non-zeroed ones pretty quickly. This surprises me; I would have expected them to have run the list through the JtR mill before passing it on to others.

Re: 6.5 Million LinkedIn Password Hashes Leaked

#393

Post by dudus » Wed, Jun 06, 2012, 6:33 PM UTC

Yoms wrote: post #245

riffraff wrote: post #232

Earlier quoted context omitted.

fwiw, this could also be an elaborate hoax, given this facts. E.g. a list of simple password + combinations of the above simple password+"linkedin" variations.

My complex unique password is also on this list (full hash no 5 0's). So nope, not a hoax. Unbelievable/insulting they didn't even bother to salt.

I couldn't find my password on the list and I've been using the same password for LinkedIn since I registered. I was trying to remember when was that. If someone know how to find out the last time you changed your pass or when you registered for linkedIn please let me know. I'd guess I use linkedIn for over 4 years at least.

Re: 6.5 Million LinkedIn Password Hashes Leaked

#394

Post by mdavidn » Wed, Jun 06, 2012, 6:35 PM UTC

tptacek wrote: post #259

leif wrote: post #63

Earlier quoted context omitted.

Pbkdf2 is extremely good. Without deeper analysis (or a feature comparison) I'd be hesitant to say that bcrypt or scrypt are better.

I sincerely mean no offense but this statement came directly out of your butt. Read the table on page 14 of Colin Percival's Usenix paper "Stronger Key Derivation Via Sequential Memory-Hard Functions" (which you could have found by Googling [scrypt paper]); PBKDF2 is ~5x faster (ie: costs ~5x less to break) than bcrypt; PBKDF2 and scrypt aren't even in the same ballpark. From exactly where did you derive the idea tha…

Eh? PBKDF2 has configurable complexity and has found many more applications than bycrpt, from WPA2 to disk encryption. The crypto research behind PBKDF2 is much more rigorous.

Re: 6.5 Million LinkedIn Password Hashes Leaked

#395

Post by zenocon » Wed, Jun 06, 2012, 6:40 PM UTC

If this is legit, shouldn't LinkedIn be notifying users of the security breach?

Re: 6.5 Million LinkedIn Password Hashes Leaked

#396

Post by tptacek » Wed, Jun 06, 2012, 6:41 PM UTC

mdavidn wrote: post #394

tptacek wrote: post #259

Earlier quoted context omitted.

I sincerely mean no offense but this statement came directly out of your butt. Read the table on page 14 of Colin Percival's Usenix paper "Stronger Key Derivation Via Sequential Memory-Hard Functions" (which you could have found by Googling [scrypt paper]); PBKDF2 is ~5x faster (ie: costs ~5x less to break) than bcrypt; PBKDF2 and scrypt aren't even in the same ballpark. From exactly where did you derive the idea tha…

Eh? PBKDF2 has configurable complexity and has found many more applications than bycrpt, from WPA2 to disk encryption. The crypto research behind PBKDF2 is much more rigorous.

Please cite one academic cryptography paper that presents an analysis of PBKDF2, other than Colin's paper which damns it.

There is virtually no "rigorous" research into KDFs of any sort, let alone password KDFs. Most academic crypto research simply presumes passwords are taken from cryptographically secure random number generators and stored securely.

And with that said I want to remind you that I just cited a source, accepted at Usenix, that measured PBKDF2, bcrypt, and scrypt and found PBKDF2 inferior to bcrypt. You seem to want to pretend otherwise.

Re: 6.5 Million LinkedIn Password Hashes Leaked

#397

Post by daurnimator » Wed, Jun 06, 2012, 6:42 PM UTC

madmaze wrote: post #204

jgrahamc wrote: post #170

Some observations on this file: 0. This is a file of SHA1 hashes of short strings (i.e. passwords). 1. There are 3,521,180 hashes that begin with 00000. I believe that these represent hashes that the hackers have already broken and they have marked them with 00000 to indicate that fact. Evidence for this is that the SHA1 hash of 'password' does not appear in the list, but the same hash with the first five characters…

I disagree with #5, I had a few of my coworkers check their sha1 against the DB and most of them were not in the dump. I also checked for truncated hashed, none of which were found. I have the feeling this is a subset of the full database

My linkedin password of at least 3 years was not in the dump. So it must be a partial...

Re: 6.5 Million LinkedIn Password Hashes Leaked

#398

Post by kylog » Wed, Jun 06, 2012, 6:43 PM UTC

iand wrote: post #257

thaumaturgy wrote: post #205

Earlier quoted context omitted.

Hmm. My truncated password (for my now-deleted account) is not in the list of hashes -- so it's not just a uniq'd full DB. Also, the original forum thread where the file was first posted only managed to break around 600,491 passwords before it went offline ... so 3,521,180 broken passwords could mean that the original hacker has had access to some LinkedIn accounts for more than just a few minutes today.

Same here. My password is not in the list and I've had a LinkedIn account since 2003. I probably changed my password about 18 months ago. Neither that nor the previous one are on the list.

My password is not in the list, not idiotic but not super-hard . I doubt this is the full list. I hadn't changed mine in years, so maybe this is from a certain period of time?

Re: 6.5 Million LinkedIn Password Hashes Leaked

#399

Post by slavak » Wed, Jun 06, 2012, 6:45 PM UTC

vivekian2 wrote: post #329

dpritchett wrote: post #260

Earlier quoted context omitted.

Here's node.js: $ echo linkedin | xargs node -e "var x = require('crypto').createHash('sha1').update(process.argv[1]).digest('hex'); console.log([x, '00000' + x.substring(5)]);" 7728240c80b6bfd450849405e8500d6d207783b6 0000040c80b6bfd450849405e8500d6d207783b6

Or you could just feed "sha1 " to the duckduckgo.com search box and it will give the result.

Some people have this thing against sending their private passwords in plaintext to third-party websites...

Re: 6.5 Million LinkedIn Password Hashes Leaked

#400

Post by ghshephard » Wed, Jun 06, 2012, 6:45 PM UTC

lt wrote: post #286

jgrahamc wrote: post #170

Some observations on this file: 0. This is a file of SHA1 hashes of short strings (i.e. passwords). 1. There are 3,521,180 hashes that begin with 00000. I believe that these represent hashes that the hackers have already broken and they have marked them with 00000 to indicate that fact. Evidence for this is that the SHA1 hash of 'password' does not appear in the list, but the same hash with the first five characters…

Another data point: I changed my linkedin password about three weeks ago. The old one is in the list (already 00000-ed), the new one isn't.

I don't know if I have the correct file: http://www.mediafire.com/?n307hutksjstow3

mbf041:Downloads shephard$ wc -l SHA1.txt 6143150 SHA1.txt

My password hash which was last rotated July 5, 2011

   .,7^R8Cl}g1}Ze6f

Was _not_ found in the file (with/without 00000). I have, of course, changed it today. Strangely enough, the previous password is also not in the list.