I've read the password8 cracking guide. However, I'm a little confused. I'm generating my own rainbow tables using rtgen, which will mainly be used for ntlm cracking. I will be using my own passwords for cracking. I want to understand how rainbow tables work and how much time they actually save. So I downloaded winrtgen to see what kind of dimensions I should make the tables.

I inputed ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489__1.

So I'll be generating a table for ntlm, lowercase alpha with 0-9 and the 14 symbols, minimum password length of 1, and maximum password length of 8, 0 for index, 20,000 chain length with a total of 97505489 chains in the table. I was using the guide that came with password8.html in the remote exploit password cracking guide by J. Dravet. He was suggeting using only 120 tables. So inputed all these specs in winrtgen and this only yielded 93 percent accuracy of finding the right match. So I inputed 200 tables which gave 98.7 percent accuracy. I think it was gonna be a total of 345 gigs or so. I have a spare 500 gig hard disk so I was gonna use the disk exclusively for the rainbow tables. So I setup a script

#!/bin/bash
i=1
while [ $i -lt 201 ]; do
sudo /pentest/password/rcrack/rtgen ntlm loweralpha-numeric-symbol14 1 8 0 20000 97505489 _$i
let i=i+1
done

So that I can generate 200 tables. I started this morning and I can tell this is going to take weeks. Not to mention sorting all the tables afterwards. How long does sorting take relative to generating the tables? I don't mind leaving my comp on since the cpu temps are in check. Of course, this huge table is only good for lowercase-alpha-numeric-14symbol passwords. So if the password has one uppercase char then this table is no good. I could imagine that adding uppercase alpha would increase the size of the rainbow tables exponentially. Anyhow, 345 gigs for these tables seems a bit extreme, but I don't mind, just wondering if I'm doing it right, cause the guide was suggesting that the tables could fit on a DVD, hehe. I have a feeling I'm misunderstanding it, cause a pentester friend of mine said that he had rainbow tables that were only 17 gigs.

Also, so let's say I generate the 200 tables. I will have

ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489__1
ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489__2
ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489__3
all the way to _200

Then when I try to crack a hash, how would it be done?

I mean I thought that the rainbow tables would just be on one big rt file instead of several of them. So to crack a hash I would use

sudo rcrack *.rt hash.txt ??

Seems like my comp can complete 1 table in 16 days. So 200 tables, hehe 200 days, damn. So what am I doing wrong? I do remember in that guide I mentioned, the guy suggested 120 tables, using the same specifications, which would be 120 days. What am I missing here?

So I see it can take about 3.58 years to generate 120 tables, hehe. So I guess you're better off downloading a torrent of rainbow tables.