Sick! Congratz! How long did it take you? Was it pretty intuitive? I'd like to make more, and any feedback is appreciated!

Yeah I was totally over thinking it at first so it took me like 2-3ish hours (some of that time was thinking through it while doing other things). But, this was totally doable. Probably shouldn't have taken me as long as it did lol

I will say, you didn't quite have the complete address. It took some experimenting to figure out what was missing (I figured out that each day increments the "missing bit", so incrementing backwards worked). Wasn't sure of that was an intentional part of the puzzle, but I'd watch out for that if not. Obviously you can't reveal the hex code from the beginning again, but you could definitely make it part of the "solution" next time.

I'd love to keep doing more of these, I hope this generates more interest. I'm also very into cryptography, so if you ever want to collab down the road, hmu at I love solving this kind of thing (and stacking, obv lol), but I'd definitely enjoy helping build it as well.

Oh and also, calling it "sats CTF" or "btc CTF" or something giving it a clever name (w/ CTF) will make it more searchable for future reference

Ooooh snap, I didn't even realize about the day counter on that site, I thought that number didn't change so I was like "eh if they play around on this site they'll figure it out" so double congrats on getting past that mistake haha!

Definitely down to make more, maybe eventually we get a weekly featured treasure hunt going @k00b


And ty, never heard of CTF in this context, good idea, wasn't sure if "bounty" was the right word either. Thanks for all the feedback!

I have also been thinking about sats CTFs but I haven't figured out where the reward pool should come from. Don't want to fund all these challenges myself lol.

I thought about deposits if someone wants to take the challenge so only winners (limited time?) get a reward. But that could sound untrustworthy and a time limit is also not very fun.

Another possibility would be that the first winner gets 50% amount of the sats, the second 25% and so forth.

Then multiple people can win but funding the challenges long-tern is still a problem, I think.

I don't have Twitter, do you have nostr? Then I can shoot you a message if I ever come up with a prototype or something.

A problem with multiple payouts per challenge are sybil attacks:

The first winner can create multiple identities and thus win the challenge multiple times if something like LNURL-auth is used.

Maybe I am overthinking this and I should just build? ... lol

I've had the same thoughts, about funding them and about how to design them so that multiple people can win. Perhaps there's something there with NOSTR, I haven't set mine up yet but will soon.

I've thought about maybe a system where a slow release of smaller puzzles that each lead to a clue, and a reward if you're the first to solve it. The small puzzles can be dropped at regular intervals (blocks?) so people know when to look for it. They could even be made difficult, such that multiple puzzles are active at a time. The clues could then lead to a larger puzzle with a bigger payout and be (potentially) unsolvable until each of the smaller ones are unlocked.

Again, doesn't really solve the long-term funding issue haha! But it's a fun hobby for now