Research Paper on Cryptography

jeremy8529

Hello Tech Exams.net! I am performing a research project for a scholarship on cryptography, and I need some help designing my experiment. My thesis is going to be something on the lines of " Windows XP passwords can be cracked within.... depending on this given complexity with this much processing power.", and I am wanting to try cracking windows passwords using various methods starting with OPH crack, and then moving on to other brute force/dictionary attack methods. Then i'm going to compare the methods, and the time it took to crack each password with each given method. I was wondering if the tech exams community had comments or suggestions on how I should design my experiment, and if they know of any way to calculate how long it would take to brute force a certain password with a certain amount of processing power.

kimanyd

I don't think there's an easy calculation since so much would be dependent on the systems in question. Just try to get your hands on a few different systems and benchmark the various processes on all of them.

jeremy8529

If im wanting to test a classical dictionary attack, what tool would you recomend that I use? What about a tool that uses rainbowtables to find a matching hash for a md4 or md5 and if I was wanting to see how long it would theroreticly take to match a hash generating a new one each time (brute force) what tool would you recomend?

So Three Methods Im wanting to test, Dictionary, Rainbowtable, and Bruteforce what three hopefully free tools can I use to test these. (Im thinking about omiting the traditional dictionary attack)

kimanyd

John the Ripper password cracker
oxid.it - Cain & Abel
Ophcrack

jeremy8529

Thanks man!

bgrablin

Could this be social engineering of techexams.net, someone looking for advice into cracking WinXP passwords? Or am I just over cautious being that I have just completed Sybex's Security+ book. Who knows? I won't touch this with a 10 foot pole.

kimanyd

That's funny, but I think trying to social engineer information that's publicly available is a waste of time

Many security books cover those tools, and they're easily discovered with a few simple Google queries.

Met44

These sites offer some interesting information, particularly the first one. I would be careful about using them as a basis of reality, but you may be able to describe how accurately some of the "password recovery calculators" available on the Internet match up with your findings.

http://www.lockdown.co.uk/?pg=combi
Online Password Calculator

jeremy8529 wrote:

I was wondering if the tech exams community had comments or suggestions on how I should design my experiment, and if they know of any way to calculate how long it would take to brute force a certain password with a certain amount of processing power.

The attack descriptions on lockdown.co.uk attempt to address part of your second question. However, porting their information from what they appear to be doing into another situation may be a difficult translation, particularly if you get into salted password hashes or the assumption that you may not be able to obtain the hash. Something to think on.

seuss_ssues

I think a better topic would be to compare password length vs complexity. You could do that research on a single PC rather trying to benchmark separate systems.

So whats harder to crack?
p@ssw0rd or thisismyreallylongandobnoxiouspasswordwithnosymbolsornumbers

Edit: Dunno why its throwing a space in the long password.

jeremy8529

^
No, this isn't an social engineering attempt lol, I too have studied security quite thoroughly and have heard of all of these tools at one point in time or another, but I didn't know which one would suite my experiment best. I believe that I will go with seuss's advice and only test on one computer. What I am still deciding between is this, should I test just windows XP LM hashes, or do you think it would make a better experiment to test MD4 hashes used by as well MS CHAP v-1 using the same passwords of course. All in all what I am asking now, what do you think would make the most interesting experiment?

Right now what I have in mind is this, try six passwords just for example here....
carheart
CarHeart
carheart343
CarHeart343
c@rhe@rt343
C@rHe@rt343
@hCr@rT432
and I will run them through the MD4, and LM, algorithms, then compare how long it would take to break each password using brute force,dictionary, and finally a rainbow-table. Make some graphs of the data, and then start of my paper. The only thing is, what am I testing to see? Do I want to say that " Passwords under a certain length and complexity and susceptible to being broken with X amount of time", or do I want to say perhaps " To decrease the odds of your password being broken you must create a password that is at least X characters long with Y letters, and Z symbols?"