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Team Bill E Ghote
Graph of Bill E Ghote's score over time
||John the Ripper, OphCrack, RainbowCrack, custom mutation scripts
One HP 8440p laptop (dual core i7 M)|
I did not prepare at all for the event, and only learned about it on
Thursday when I picked up my DefCon badge. I should pay more attention,
probably. I also did not get the hashes until late in the day Friday, so
I did not take advantage of the full time window. My score would have
been somewhat better, but not substantially more competitive due to my
lack of available hardware. In fact, I knew that I was at a disadvantage
and fully expected to come in dead last. That I did not says something
about the other participants, for sure. To quote a bumper sticker I saw
recently: Try Harder!
My own approach was to use JtR to crack each of the hash types using my
existing pot file to seed the rest of my effort. I let JtR continue to
run in incremental mode in parallel sessions, while at the same time
running OphCrack in batches of 10 against the LMNT hashes. I used custom
shell scripts to mutate the cracked passwords and cross-feed the mutated
data back into JtR wordlist sessions against each of the hash types. Due
to my own limited hardware, I was forced to stop the incremental cracking
against the harder hash types (blowfish, md5, Oracle). In fact, after a
bit, I stopped all the incremental sessions and simply focused on
OphCrack, feeding the results back into JtR.
Rather late in the competition time window, I realized that OphCrack was
dumping the : character as a non-ASCII character, which JtR did not
appreciate. Converting that to the : character would have improved my
results had I gotten there before the contest window closed.
The poor HP laptop was hurting bad from all the active processes. RAM was
not a constraint as much as available CPU. Keeping them spun up at 100%
taxed the cooling system. I let processes run while I took the laptop
with me to watch presentations at the con. If I had not connected to AC
power while there, I would not have made it two hours on the battery - the
same battery that typically stays up over four hours on a light load.
Server hardware would definitely be better suited for the contest, to
restate the obvious.
If we do it again next year and I manage to get back out to Vegas, I'll do
it right. Might even invite some friends along for the party. There
should be a party, too.