If you can solve this puzzle, you can earn 3 million USD.
The puzzle was given to me by a friend of mine. He claims that his friend owns a Math wallet account with 800 Ether, but he cannot transfer funds out of this wallet.
Here's the Ethereum address: 0xdcc703c0E500B653Ca82273B7BFAd8045D85a470
Click on the comment section, and you'll see this comment:
CAUTION! If your final address looks like 0xdcc703c0E500B653Ca82273B7BFAd8045D85a470 this means you have hashed an empty public key. Sending funds to this address will lock them forever!
And it links you to this article where you see more discussion about this particular address. If you generate the key pairs improperly, there's a good chance that you may end up with a "blockhole" address where funds can never be transferred out.
Are you a cryptography expert who knows how to solve this? That may allow you to unlock the funds in this account, which is worth more than US$ 3m today!