Hey guys,
Today I'm gonna show you a really cool challenge site - Ma's Reversing at http://www.3564020356.org.
This is one of the very first challenge sites on the Internet. There are a total of 28 riddles and you have to solve them sequentially. After solving the riddle you can see the solutions to it and discuss about it in the next riddle forum.
The riddles cover many aspects of the computer world, from steganography, cryptography, to reversing. While solving the riddles, you feel like being drowned into the long history of computing. And there's always something to learn from them.
The site owner, Malatia, has been inactive for quite a while. But thanks to the educative and challenging riddles, the site is still alive :)
The site is available for free, but only to those who deserve it. Everyone needs to pass a qualifying riddle in order to become a member. But don't worry, just put some effort into it and the sesame will open for you :)
Monday 29 October 2007
Friday 26 October 2007
slyfx
Hey guys,
Today I would like to introduce an old but really nice challenge site: slyfx at http://www.slyfx.com.
Like many challenge sites at the time, slyfx has 10 levels, from easy to hard. There are 3 challenges per level, and you have to solve 2 of them to advance to the next level. The challenges, which vary from logic, programming, reversing and exploiting, will give you a nice tour in the world of computers.
Unfortunately, just like Arcanum, with the limited number of challenges, slyfx is only good as an introduction to wargaming.
Today I would like to introduce an old but really nice challenge site: slyfx at http://www.slyfx.com.
Like many challenge sites at the time, slyfx has 10 levels, from easy to hard. There are 3 challenges per level, and you have to solve 2 of them to advance to the next level. The challenges, which vary from logic, programming, reversing and exploiting, will give you a nice tour in the world of computers.
Unfortunately, just like Arcanum, with the limited number of challenges, slyfx is only good as an introduction to wargaming.
Bits and Bytes
Bits and Bytes,
a very basic tutorial with introduction to steganography.
First you should know that this information here is kept very basic and not very accurate. If you find some horrible mistakes please leave a comment. I tried to use easy vocabularies because this post is targetted on beginners.
I. A computer is like a big calculator.
The only thing it can do is calculate numbers, which are stored in binary format.
The binary format, numbers represented in base 2, are used because you can easily represent the two possible binary digits (0 and 1) with electric power (voltage on or voltage off). Everything what your computer does is just computing lots of these binary numbers, and send or recieve those numbers to/from other components. Your monitor for example shows colors, that represent certain numbers and your keyboard sends some numbers to your computer when you press a key.
A computer can only compute a small range of bits at once, which depends on the processor (usually 32 or 64 bits today).
Also it can address its memory only in byte steps (byte aligned).
A group of 8 bits is called a byte and can hold 256(2^8) different numbers (from 0 to 255).
In the beginning of computers there was the need for a codetable that converts numbers to letters.
This codetable is called ASCII-Table .
It uses 8 bits (1 byte) to represent one character.
An example: You can see that the number 65 represents an 'A'.
65 in binary is 01000001. (Try out the windows calculater and use the scientific view, you can convert numbers from binary to decimal beside other things with it)
- - - - - - - - - -
II. As you migth know, steganography is the art of hiding a message.
For example using invisible ink and write with that ink between the normal lines.
In the age of computers there are lots of ways to hide data inside other data,
but lets focus on very basic stuff; Bits and Bytes.
In computer age you can even hide letters due hiding its bits.
Ill "hide" the string ABC in some garbage data applying this rule:
Alernately take one bit of the message and one bit of the garbage.
like: M = Message; G = Garbage
MGMGMGMGMGMG....
ABC: 01000001 01000010 01000011
Garbage: 11110000 11110000 11110000
Mixed up: 011101010000001001110101000010000111010100001010
MGMGMGMGMGMGMGMG.....
You can easily decode this by using only every second bit, starting with the first.
You could also use your own codetable to represent letters, like A = 1, B = 2 and so on, what will need less bits than ascii.
Also its possible to just not use the highest bit (which is always 0 in standard ascii), or even not use the leading '01', cause all letters start with a binary '01'.
a very basic tutorial with introduction to steganography.
First you should know that this information here is kept very basic and not very accurate. If you find some horrible mistakes please leave a comment. I tried to use easy vocabularies because this post is targetted on beginners.
I. A computer is like a big calculator.
The only thing it can do is calculate numbers, which are stored in binary format.
The binary format, numbers represented in base 2, are used because you can easily represent the two possible binary digits (0 and 1) with electric power (voltage on or voltage off). Everything what your computer does is just computing lots of these binary numbers, and send or recieve those numbers to/from other components. Your monitor for example shows colors, that represent certain numbers and your keyboard sends some numbers to your computer when you press a key.
A computer can only compute a small range of bits at once, which depends on the processor (usually 32 or 64 bits today).
Also it can address its memory only in byte steps (byte aligned).
A group of 8 bits is called a byte and can hold 256(2^8) different numbers (from 0 to 255).
In the beginning of computers there was the need for a codetable that converts numbers to letters.
This codetable is called ASCII-Table .
It uses 8 bits (1 byte) to represent one character.
An example: You can see that the number 65 represents an 'A'.
65 in binary is 01000001. (Try out the windows calculater and use the scientific view, you can convert numbers from binary to decimal beside other things with it)
- - - - - - - - - -
II. As you migth know, steganography is the art of hiding a message.
For example using invisible ink and write with that ink between the normal lines.
In the age of computers there are lots of ways to hide data inside other data,
but lets focus on very basic stuff; Bits and Bytes.
In computer age you can even hide letters due hiding its bits.
Ill "hide" the string ABC in some garbage data applying this rule:
Alernately take one bit of the message and one bit of the garbage.
like: M = Message; G = Garbage
MGMGMGMGMGMG....
ABC: 01000001 01000010 01000011
Garbage: 11110000 11110000 11110000
Mixed up: 011101010000001001110101000010000111010100001010
MGMGMGMGMGMGMGMG.....
You can easily decode this by using only every second bit, starting with the first.
You could also use your own codetable to represent letters, like A = 1, B = 2 and so on, what will need less bits than ascii.
Also its possible to just not use the highest bit (which is always 0 in standard ascii), or even not use the leading '01', cause all letters start with a binary '01'.
Steganabara
Hey!
most of you will know me by the nick 'theAnswer'.
In my first post I want to present to you a great tool called Steganabara that helps you to solve steganos (to be exact: visual image steganos). It was coded by my dear friend quangntenemy in Java. Some of the functions it contains:
It doesn't show you the solution for a challenge instantly (sometimes it does :)), it's more an analysis tool.
The current official version is 1.0.8 and you can get it at quangntenemy's site:
http://www.freewebs.com/quangntenemy/
Try it out!
ozehka
most of you will know me by the nick 'theAnswer'.
In my first post I want to present to you a great tool called Steganabara that helps you to solve steganos (to be exact: visual image steganos). It was coded by my dear friend quangntenemy in Java. Some of the functions it contains:
- Color Explorer (Red-, Green-, Blue- and Alpha-channel)
- Histogram
- Color Table (with frequencies)
- Bit Mask Filter
- Filter by Color Map
It doesn't show you the solution for a challenge instantly (sometimes it does :)), it's more an analysis tool.
The current official version is 1.0.8 and you can get it at quangntenemy's site:
http://www.freewebs.com/quangntenemy/
Try it out!
ozehka
Thursday 25 October 2007
Arcanum
Hey guys,
I would like to introduce Arcanum, one of the very first challenge sites I played.
I would like to introduce Arcanum, one of the very first challenge sites I played.
The site was located at http://www.arcanum.co.nz, but unfortunately it is now down since the domain expired. The Arcanum enthusiasts are still idling on #arcanum at irc.idlemonkeys.net. flamecruiser is trying to revive it so maybe one day it will be back again :)
Arcanum tests your skills in 4 different categories: logic, programming, encryption and unknown. There are 6 levels of difficulty. You have to pass all challenges at a level to advance to the next one.
When I joined Arcanum, as a beginner, the challenges were really interesting and educational. With basic computer knowledge and a little bit of research, I was able to solve all the challenges and ended up in rank #147.
The only bad thing about Arcanum was that there were not many challenges, and they weren't too hard. A challenger like me probably would only stay until he has solved all the challs and move onto the next one.
Update: Thanks to Whiteboy the site is up again at http://arcanum.fxfi.net/. Check it out!
Arcanum tests your skills in 4 different categories: logic, programming, encryption and unknown. There are 6 levels of difficulty. You have to pass all challenges at a level to advance to the next one.
When I joined Arcanum, as a beginner, the challenges were really interesting and educational. With basic computer knowledge and a little bit of research, I was able to solve all the challenges and ended up in rank #147.
The only bad thing about Arcanum was that there were not many challenges, and they weren't too hard. A challenger like me probably would only stay until he has solved all the challs and move onto the next one.
Update: Thanks to Whiteboy the site is up again at http://arcanum.fxfi.net/. Check it out!
Welcome
Hey guys,
If you are a challenger, you have come to the right place ;)
This blog is dedicated to computer-based challenges, aka wargames, hacker games, etc.
Here you will find:
Happy challenging!
If you are a challenger, you have come to the right place ;)
This blog is dedicated to computer-based challenges, aka wargames, hacker games, etc.
Here you will find:
- A comprehensive list of all the cool challenge sites, together with detailed reviews about them.
- Links to online resources, tutorials, and tools.
- Tips, tricks and tutorials from the top challengers.
Happy challenging!
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