I am back :)

Hi everyone !

After being away from cracking and stuff .. (for a really long time) .. I am back again :)

- Submitted Solution to Obnoxious' Obnoxious Crackme. (Will be posting here soon)
- Reverted all "linkbuck"ed links to original :)
- Solving one of costy's crackmes.

Indomit's solution to my KeyGenMe #5

CrackMe Location :: KeyGenMe #5 @ Crackmes.de.
Solution Location :: Solution by indomit.

So, the main goal of crackme is win the game. As we knew in the Tic-tac-toe game (3x3 grid) the best strategy of both parties leads to a draw. So, to beat the computer there must be a weakness in algorithm. And there it is! If we put "X" in center, the computer always bring to a draw; If we put "X" in any side but not corner, the computer always win; But if we put "X" in corner, there is one weakness that helps us win:

After we put "X" in corner, computer always put "O" in center:
X - -
- O -
- - -

Then, if we want win, the best way is put "X" in an opposite corner:
X - -
- O -
- - X

After this, the best computer move is put "O" at any side (not corner!), but in crackme it moves into corner:
X - O
- O -
- - X

At this point we have already won ;). Just put "X" in empty corner and there is fork :)
X - O
- O -
X - X

Now, computer can't do anything to win or draw :)
This was the main logic. Read the complete solution (in my box or from crackmes.de) for further details.

Solution to indomit's The Cattle Crackme

CrackMe Location :: indomit's The Cattle Crackme @ Crackmes.de.
Solution Location :: Solution @ Crackmes.de by me.

MY RATING :: Quite Nice !
PLATFORM :: WINDOWS
LANGUAGE :: .NET
DIFFICULTY :: 3 [ Getting harder ]
TOOL(S) USED :: Reflector

Overview:
=-=-=-=-=
(*) Lots of tedious equation solving and a bit of number theory make it a nice crackme to solve.

Read the solution to find more about it. :)

KeyGenMe #6 :: .NET :: Difficulty : 4 [HARD !]

KeyGenMe Location : KeyGenMe #6 @ Crackmes.de
Solution Location : Not Solved Yet.

One of my hardest KeyGenMes yet !! KeyGenMe #5. It's coded in VB.NET. Features :
(*) NOT Packed
(*) NOT Encrypted
(*) Kool GFX 'n' SFX

The Rules :
(*) NO Patching
(*) NO Brute-forcing

The Tasks :
1. Find the algorithm for the computations involved.
2. Try to get Status as ":-)".
3. Make keygen to VALID Key for ANY name. Please note that VALID KEYS EXIST FOR ALL NAMES.
Keygens able to generate multiple keys for each name will be preferred.
4. Write a descent tutorial. ;)

The Hint :
==========---
It's .NET, you've the source code ! So, no hints.. ;-)

Readers, if you solve this, please upload your solution to CrackMes.de.