You probably saw this one several months before: 1 bitcoin hidden in the puzzle. I missed it when it was just published, but the idea itself is quite good.
Then I was interested to find other puzzles related to cryptocurrency. Not necessarily new, where I can still win something (though, it would be cool too), but even those I have not seen yet, just to take fun and test myself. Maybe you will find something interesting here. Or maybe add other sources.
At the moment I could find not so many good ones. Here's something related to:
Hidden Bitcoin In No Man's Sky Game
Reddit for all of your Bitcoin related puzzles and scavenger hunts
Review of some solved puzzles
And several others
Hehe, hiding it in the No man's sky is actually pretty fun idea. I wonder how much it's going to be worth when it's been found