As if there wasn't enough to learn in the world of crypto, some weeks ago, I stumbled upon an entirely new aspect of it - Crypto Puzzles. Although the idea of puzzles isn't entirely new, cryptocurrencies facilitate puzzles in a very elegant and seamless way.
The puzzles come in different shapes and flavors and present some sort of riddle/mystery that needs to be solved. When creating such a puzzle in times before crypto, there was always the question, of what people should look for / what the answer to the puzzle will look like. In addition, the creator of the puzzle had to think about and handle the payment process.
Cryptocurrencies to the rescue
With cryptocurrencies, both of these aspects are taken care of. The final answer is always the private key of a wallet and the reward is collected by transferring the funds away from the puzzle-wallet to the winners-wallet.
The Legend of Satoshi Nakamoto
The whole puzzle world was brought to my attention when the famous "1FLAMEN6" or "The Legend of Satoshi Nakamoto" puzzle was solved. It had so many fascinating and impressive aspects, that I decided to dedicate some time to this topic. If you're interested in the solution of the 1FLAMEN6-Puzzle, I can recommend the following article:
One of the most interesting aspects of the 1FLAMEN6-puzzle is the fact that it is a painting and still contains all information necessary to decode a private key from it.
The 210-LTC Puzzle of Charlie Lee
Another great example of a crypto puzzle is the 210-LTC Puzzle from Charlie Lee. The solution is documented by 
This should give you an idea, how these puzzles are structured and the shapes and flavors they can be presented. Unfortunately, this also shows how tricky and time consuming these puzzles can be. More examples of mostly solved puzzles can be found on the following website: http://crypto.haluska.sk/
Unsolved and upcoming puzzles
Now that I spent some time talking about puzzles that have already been solved, I also want to present some that have not been solved yet.
The Neon District Puzzle
Neon District itself is a game that is planned to be launched on the Ethereum blockchain. Besides the fact that it is already an interesting project by itself, in addition, there is a crypto puzzle hidden in the project.
It was first brought to my attention by a Twitter post of Ben - 
Having a close look at the whitepaper, I found some footnotes to be missing and having a real close look, I found out that they aren't missing but written in white font on white background. If the three missing footnotes are collected, they assemble the following sentence:
- Footnote 1 - Find
- Footnote 4 - The
- Footnote 6 - Terminal
So the puzzle seems to be real and if you get back to the Neon District Website to have a look at the source code, this is the part that leads you to the terminal:
// Accept input for opening the terminal
$(document).on('keyup',
TerminalEntrance.sequence(38, 38, 40, 40, 37, 39, 37, 39, 66, 65, initTerminal)
);
These are the very first steps of this puzzle and the race is on until the following wallet is empty:
If you want to join the competition, I'd recommend the Neon District Discord Channel. But be prepared for some headaches and sleepless nights. Personally, I'm not sure if I have what it takes (time and knowledge) to have a real chance of solving this one, but it fascinates me so much, that I wanted to write about it. For this puzzle, I got to the stage called "The Gateway" (almost) by myself, but things seem to get very, very tricky from there.
MonteCrypto
After having a look at these computer science/cryptography heavy puzzles I stumbled upon an interesting alternative while watching 
I'm very excited to see how this branch of the crypto world develops and whether or not we will see more puzzles and variety in puzzles in the future.
Let me know what you think and leave your questions, feedback, and comments below.
Thanks for reading!
Cheers
BTW: To learn about the mindset of puzzle solving, I consider this to be an interesting read: Thinking About a Puzzle - by Allen Rabinovich