Puzzle-gated prizes,
private by design.
Privacy first. Solve puzzles without being known.
Hide shielded ZEC behind a riddle. Guesses never leave the solver's browser, anyone can verify the prize is real, and nobody can see who won.
No account, no email, no tracking. New here? Play a one-minute hunt.
Follow one guess
Scroll to see where your guess goes.
- 1You type a guess
It appears in your browser. That is the only place it will ever exist.
- 2Your browser does the hard work
Argon2id stretches the guess through 64 MiB of memory into a key. A bot pays that same price for every single try.
- 3The key tries the lock
Wrong guess: the lock stays shut and nothing happens. Right guess: the stage decrypts, right here on your device.
- 4The server saw none of it
No guess, no result, no progress. It served the locked hunt file, and that's all it knows.
- 5One request, one shielded payment
The final answer unlocks the prize key. One claim request carries it with your payout address, and the prize leaves in a shielded Zcash transaction. Prefer not to tell the site your address? Sweep the pot yourself with the unlocked key.
- 6The chain doesn't show who won
Anyone can check the pot was emptied. Nobody reading the blockchain can see where the prize went or how much. Sweep the pot yourself and this site never learns your address either.
How it works
Three steps. Your answers never leave your browser.
The cryptography happens in your browser; the prize lives in Zcash's shielded pool.
Hide
Write the riddle
Clues and answers, stage by stage. Your browser makes the prize key, locks each stage with its answer and seals the key inside the last one.
Prove
Fund it in the open
Send shielded ZEC to the hunt's pot. Its viewing key is public, so anyone can check the prize is really there.
Solve
Unlock and claim
Each right answer opens the next clue. The last one unlocks the prize, claimed in a single shielded transaction.
See for yourself
Your guesses stay yours.
Every guess is stretched with Argon2id and tried against the locked stage, right on your device. Wrong or right, nothing is sent. Open the Privacy X-ray on any page to watch it live.
- No guess ever reaches the server
- The server can't tell how far you got
- Bots pay 64 MiB of work for every try
Privacy
Private by design. Provable by anyone.
Most "prize" apps ask you to trust them with your answers, your identity and the payout. Here the trust is replaced by math, and what can't be removed is written down.
Guesses stay on your device
Every guess is checked by trying to decrypt the stage locally. Wrong or right, nothing is sent.
The server holds ciphertext
Hunts are stored locked and padded to equal sizes. Nothing the site stores can reveal an answer, a later clue or the prize key.
The prize is verifiable
The pot's viewing key is published. Check the balance in any Zcash wallet, without trusting us.
The chain doesn't show the winner
The payout is one shielded transaction, built so even the public viewing key can't see where the prize went or how much was sent.
Who learns what
No fine print: every party that could learn something, and what they get.
- That a pot exists and what it holds, through its public viewing key
- Deposits into it and any memo on them
- That it was emptied
- Who won
- Where the prize went or how it was split
- Who funded it, if it was funded from a shielded balance
- Your internet address while you browse, and which hunt pages you open (used for rate limits in memory, never logged)
- The pot’s viewing key, when the creator’s browser registers the pot
- On a one-click claim: the unlocked seed phrase and the address you paste
- The prize key while a hunt is unsolved: it is made in the creator’s browser
- Your guesses or answers
- How far you’ve got
- A private hunt’s title, first clue or invite key
- Your payout address, if you sweep the pot yourself
- Your internet address, and which transaction you looked at
- Anything from us: the site never contacts it
- The link itself, including a private hunt’s invite key
- Your progress or answers: they aren’t in the link
Invite-only
Private hunts. The key never reaches our server.
Tick one box and your hunt disappears from every list. Its title and first clue are encrypted with a key that exists only in the invite link, after the #. Browsers never send that part to a server.
- Only people with your link can open it
- Right answers don't work without the invite
- The prize is still verifiable by anyone
Use cases
What people use it for
Anywhere you want to reward people for figuring something out, without collecting who they are.
Zcash onboarding quests
Teach newcomers shielded wallets by making them use one. Each clue is a lesson; the prize is their first shielded ZEC.
Meetups and conferences
Print clue cards with QR codes and hide them around the venue. Whoever finishes first takes the pot.
CTFs and puzzle prizes
Gate a bounty behind a challenge. The answer itself is the key, so there's no judge to trust and no payout delay.
Giveaways without data grabs
Run a community campaign without asking for emails, wallets or sign-ups. Winners stay anonymous.
Surprises for people you know
A birthday, a proposal, a family game. Make it private and only the people with your invite link can even see what it's about.
Team offsites and classrooms
Hand out the invite as a QR code. Your group plays; the rest of the internet sees a locked page.
Live now
Live hunts
Every prize below is verified with its pot's viewing key.
No hunts yet. Be the first to hide some treasure.
Hide your first treasure
A two-stage hunt takes about three minutes to write. Public or invite-only.