RE: NT password encryption & name service

[\"D. Clyde Williamson\" <D Clyde Williamson]

No this is correct. The entire problem with NT's broken scheme hinges
on this. Longer passwords don't make safer passwords. Yech!


Graham, Randy \(RAW\)  writes:
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 > The reason you get more possible passwords than Chris is because you
 > assume an 8 character password is ((26 + 26 + 10 + 12)^7) * (26 + 26
 > + 10 + 12) passwords, when because of Microsoft splitting each
 > password into 7 character parts (which can be decrypted seperately)
 > an 8 character password has ((26 + 26 + 10 + 12)^7) + (26 + 26 + 10 +
 > 12) possibilities.  Notice that is a + in the middle there. 
 > Likewise, a 10 character password (as you gave as an example below)
 > is actually a 7 character password plus a 3 character password for
 > decryption purposes - I come up with 12,151,280,678,248, which is far
 > less then what you came up with.  Therefore there are only
 > (74^7)+(74^3) possibilities instead of 74^10.  I actually think Chris
 > calculated too high.
 > 
 > Unless I'm misunderstanding the l0pht documentation on this terribly,
 > what it says is every password can be broken in to two 7 character
 > chunks, each chunk independent of the other.  Therefore, going from 7
 > characters to 8 characters only adds 74 additional passwords to
 > decode (assuming the character set you mentioned below).  That is why
 > someone on this list (already deleted the message, and don't want to
 > search just to get a name) said he only used 7 character of 14
 > character passwords.  Certainly 8, 9, 10, 11, and probably even 12
 > character passwords don't gain you much beyond 7 characters.  And to
 > make it all worse, Microsoft doesn't even salt the passwords, so user
 > A and user B will have the same encoded password from the same
 > plaintext.
 > 
 > If I am horribly off here, I'm sure someone will let me know.
 > 
 > Randy Graham
 > 
 > 
 > - -----Original Message-----
 > From:        Chris Williamson [SMTP:[EMAIL PROTECTED]]
 > Sent:        Thursday, December 21, 2000 6:05 PM
 > To:  [EMAIL PROTECTED]
 > Cc:  [EMAIL PROTECTED]
 > Subject:     Re: NT password encryption & name service
 > 
 > Chris Hastings was incorrect in his calculation...
 > 
 > There are only two options in L0phtcrack with special characters, one
 > with
 > 12
 > Make that (26 lowercase + 26 uppercase + 10 numerals + 12 special
 > characters)^8 with a total of
 > 899 194 740 203 776 (twice as many as Chris calculated,
 > 457,163,239,653,376)
 > 
 > and the other with 32 with a total of
 > 6 095 689 385 410 816
 > 
 > If you use a combination of any special character and increase to 10
 > characters in length you should be fairly secure
 > 53 861 511 409 489 970 176
 > 
 > Or if you are paranoid like my buddy Greg who uses 13 mixed
 > characters
 > 44 736 509 592 539 817 388 662 784
 > I reckon if he changes this once a month he should be able to stay
 > ahead of
 > a L0phtcracker
 > 
 > Regards
 > Chris Williamson :)
 > 
 > - ----- Original Message -----
 > From: <[EMAIL PROTECTED]>
 > To: Bobby Brown <[EMAIL PROTECTED]>
 > Cc: <[EMAIL PROTECTED]>
 > Sent: Wednesday, December 20, 2000 7:52 PM
 > Subject: RE: NT password encryption & name service
 > 
 > 
 > >
 > > Using this password as an example (for length and character type),
 > > the number of possibilities
 > > would be (26 lowercase+26 uppercase+10 numerals+6 special
 > > characters)^8 (assuming that the
 > > period at the end of the sentence isn't part of the password). 
 > > This is a total of 457,163,239,653,376
 > > possibilities (compare this with DES encryption at 56-bit which we
 > > all 
 > know
 > > can be brute forced at
 > > 72,057,594,037,927,936 possibilities).  If you have the period at
 > > the end 2^54 < 68^9 < 2^55 possibilities.
 > > Better but still fewer possibilities than 56-bit encryption...
 > >
 > >
 > > Chris Hastings
 > > Manager, Network Security
 > > Network Computing Services
 > > Vanderbilt University Medical Center
 > > [EMAIL PROTECTED]
 > >
 > >
 > >
 > >                     Bobby Brown
 > >                     <bbrown@allensysgrou        To:
 > "'[EMAIL PROTECTED] '"
 > >                     p.com>                     
 > > <[EMAIL PROTECTED]> 
 > >                     Sent by:                    cc:
 > >                     firewalls-owner@List        Subject:     RE: NT
 > password encryption & name
 > >                     s.GNAC.NET                  service
 > >
 > >
 > >                     12/20/2000 11:14 AM
 > >
 > >
 > >
 > >
 > >  You must have had very few users or an extremely powerfull server
 > > to 
 > crack
 > > by brute force the passwords. The password you referenced has 4 of
 > > the recommended characters I wish every user used. Upper and lower
 > > case characters, special characters, and numbers. What cracking
 > > software did 
 > you
 > > use to do this ?
 > >
 > >
 > > Bobby Brown
 > >
 > > -----Original Message-----
 > > From: Carl Ma
 > > To: [EMAIL PROTECTED]
 > > Sent: 12/20/00 12:00 PM
 > > Subject: NT password encryption & name service
 > >
 > > Hello all,
 > >
 > > After running password cracking program on our W2000 PDC server,
 > > 98% passwords
 > > are cracked out, even some very complicate passwords like -
 > > X1#!h0a_. 
 > >
 > > Is it attribute to the W2000 encryption method? I would like to
 > > persuade my boss
 > > using LDAP as name service. Appreciate any information & idea! I
 > > will summarize.
 > >
 > > Thanks & Merry Christmas!
 > >
 > > carl
 > >
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 > >
 > >
 > >
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