Sunday, December 23, 2007

Challenge Sites

The internet is full of challenge sites - those where you need to solve a riddle and reach higher rank or level, and maybe even win a prize :)

Most of these sites are dealing with computer challenges, or if to be more specific - security challenges.

Once upon a time, when I had time to spend, I got addicted to such sites, and solved or partially solved most of the famous ones.

Why I got addicted? Not recently I found out that when I encounter a problem that I can't solve it really bugs my mind, even when I leave it and go to do something else. But I like that feeling. Doing a research to solve problems is one of the things I enjoy the most, not to mention the "high" produced by solving one, which is so addictive, that I must get more of it :)

Considering the educational value, I think these sites allow you to learn random material in the best way: solving real world problems. I've always had a problem with learning stuff just to "know it when I'll need it". So this is a good and healthy way to learn and explore new stuff.

So what makes a good challenge site?

First, the site should include some kind of competition - whether it's based on site-wide ranks or levels that the user advances in.
Second, the riddles should be as clear as possible - I just can't count the number of times I tried solving something without perfectly knowing what I need to achieve. This can be really frustrating to know retroactively that the solution to the riddle you tried to solve for a couple of months is so easy, but you just didn't get the point.
And third, to allow users to work on different problems simultaneously. This really helps when you're stuck on one riddle, but then you have 3-4 more to work on. Usually fresh ideas pop up after taking a break and doing something else.

Now, because few people asked me to give then a list of challenge sites - here's a list with a short explanation of each one:

NotPron - Riddle site that is based on images. To reach the next level you need to figure out the username / password or the name of the next page.

NgSec quiz - Basic security challenge - pretty easy for the experienced ones.

TryThis0ne - Israeli security challenges. Some of them are nice, some of them are pointless.

PullThePlug wargames - Includes three different games: Vortex (exploits under linux), Semtex (network challenges) and BlackSun (advanced exploitation techniques). I've worked on Semtex for some time (reached level 11) and it taught me some things about programming network code under linux with C, raw sockets and more.

Electrica the puzzle challenge - Possibly the best and hardest puzzle challenge I've ever played. Includes math, encryption, programming, reverse engineering and more puzzles. Recommended! :)

Slyfx - Nice and pretty easy security challenge, dealing mostly with web security.

PythonChallenge - Based on the concept of notpron, pythonchallenge is by far the best way I can think of learning Python - solving riddles designed to be solved by this scripting language. Of course you can solve this levels with any programming language, but it will be much more complicated (because about half of the levels includes image processing, which goes easy with Python's PIL module). The cool thing about python challenge is that after you solve a level, you can enter a solution page that shows different python codes used to solve it.

Rankk - A challenge site that started a few months ago, also dealing with security and programming.

Mod-X - Security challenges - some of them are quite hard (level 6-8 mostly).

+Ma's Reversing - Very difficult site (not so clear though), including some really strange problems that you need to analyze for hours.

HackerGames - A portal including links to alot of challenges sites - some of them are total crap (after playing some challenges you see the same levels over and over again).

Also, two RIP sites that worth mentioning:

Try2hack - The first challenge site I've ever played, and probably one of the first sites in the world.

Arcanum - Awesome site, including logic, programming, encryption and misc. challenge for every level (7 in total). Too bad the site is dead.

Now it's your turn - if YOU have a list of good challenge sites to offer please post them as a talkback.

Happy solving!


hackme said...

what about
awesome polish site with a lot of challenges?

Anonymous said...

You can also take a look at, which is not a big site, but very challenging and has all kinds of problems including math, programming, crypto etc.