Re: Display User Password?

[Douglas Handy <dhandy@xxxxxxxxx>]

Phil,

>it take somewhere in the region of 20 minutes plus do decrypt just
*one* iSeries password on a fast PC.

FWIW, last I knew that very much depended on the length of the
password.  Assuming the old style passwords (ie not 128-char and with
lanman pwds intact), then my PC can test somewhat over 19 million
passwords per second using an AS/400 password cracker obtained off the
internet.  There are a maximum of 126,030,769,230 possible
permutations which must be tried in a worst case scenario for a 7
character or more password.  On my PC, that would take up to 6506
seconds, or about 1 hour and 48 minutes worst case.  In practice, it
is likely to find the match much sooner though.

I have a tendency to have it limit the password length and run some
initial passes though, which lets it check the following lengths
first:

  1-4 char pwds in 0.1 seconds total
  5 char pwds in 4 seconds
  6 char pwds in 163 seconds (ie under 3 minutes)
  7+ char pwds 6506 seconds (ie 1 hour and 48 minutes)

So unless your password is at least 7 characters long, my lowly PC (an
AMD 2500 cpu) can do it in under 3 minutes, but it can take
substaintially over 20 minutes if using at least a 7 character
password.  However, you can also easily segment the test ranges to
allow multiple PC's to each check a subset of the potential range, so
all it would take is 5 PC's of my vintage to find it in under 22
minutes.

I'm sure newer PC's would be somewhat faster, but I doubt it is enough
so to have a single PC lower it from 108 minutes to 20 minutes
maximum.

If you keep you password to no more than 5 characters, my PC can find
a match within 4 seconds from the time it starts the process.

I'm not aware of way of doing an actual decrypt though -- only a brute
force match.

Doug