in reply to Re: Password cracking algorithm
in thread Password cracking algorithm

hmmm. replying to one's own post... something i have sadly done before, but, but...

it seems 14 characters can now be dealt with (lanman & mswin) in *14* secs

cannot resist pointing out to those interested the timely & academic link from the politech list, mailed this morn:

http://lasecwww.epfl.ch/pub/lasec/doc/Oech03.pdf. imho a great example of how hash statistics/methodology can be leveraged. ). if nothing else the article should emphasize the importance of good hash design...

wufnik

in the world of the mules there are no rules
  • Comment on re: password cracking algorithm - 14 chars in 14 secs?

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Re: re: password cracking algorithm - 14 chars in 14 secs?
by Abigail-II (Bishop) on Jul 23, 2003 at 08:55 UTC
    Yeah, but if you read the article you notice that the set of characters is limited (no difference between upper and lower case), and the 14 chars are split into two sets of 7 chars before encrypting - both halves can be attacked separatedly.

    This means that the key space of the domain tried is about 0.03% than that of Unix passwords, if we restrict ourselves to alphanumerical passwords, like the article does. The precalculated data used in the article fits on 2 CDs. Assuming it scales lineary, for an attack on alphanumerical Unix passwords, you'd need about 12 million CDs (the keyspace is 3000 times as large, and there are 4096 seeds).

    The orginal poster asked about 16 character passwords, including "special" characters. If we assume the special characters are all printable ASCII characters that aren't letters or digits, we have a key space of 95**16. Compare this to the keysize of 36**7 of the article, the former is a tad more. If we scale the 2 CDs of the article to the problem of the OP, we'd need more than 10**21 CDs. And that's assuming you need the same amount of bytes to store a password, or crypted password, which seems unlikely.

    If the OP has a billion computers, each of them capable of checking 2**32 (4G) keys per second, it would take the OP almost 325 thousand years to exhaust the key space.

    Abigail