Introduction

Using the pool

Start with cUSDC for the clearest path. The app guides you through each wallet request.

1. Get

   Request public USDC from the in-app faucet.

2. Shield

   Convert it into its confidential ERC-7984 form, cUSDC.

3. Deposit

   Choose an amount. It is encrypted before the pool receives it.

4. Reveal

   Sign a free EIP-712 viewing request to see your own principal and winnings.

5. Win

   Stay in the pool for the next encrypted, deposit-weighted draw.

6. Leave

   Claim a prize if you have one, or withdraw your principal whenever you choose.

How the draw stays fair

When a draw begins, deposits pause and the pool freezes each eligible encrypted balance. Every saver receives a contiguous part of the selection range proportional to their deposit.

Zama's encrypted randomness selects a target inside that combined range. A saver with 60 of 100 eligible tokens has a 60% chance; a saver with 10 still has a 10% chance. The random target, comparisons, winner and winnings remain encrypted.

Weight is measured at the draw snapshot. Time held does not increase it. This keeps the odds exact, avoids empty winning slots, and keeps confidential computation bounded.

What stays private

FHE protects financial values, not the existence of blockchain transactions.

Encrypted

Deposit and withdrawal amounts

Principal and winnings

Individual odds

Random target and comparisons

Winner identity in pool events

Public

Participating wallet addresses

Transaction timing

Draw state and schedule

Participant count

Combined eligible weight

A reveal is authorized by the connected wallet and shown only in that browser session. It does not publish the value onchain.

Why principal is protected

Principal, the prize reserve and awarded winnings are separate encrypted balances. The Sepolia keeper supplies mock yield for the demo; it never takes the prize from savers' deposits. Principal remains withdrawable during every draw stage.

A production version would replace mock funding with an audited yield adapter while preserving the same separation between principal and prizes.

Timing and automation

Each pool opens for deposits for one hour. The keeper checks eligible pools every ten minutes, so a draw will usually begin roughly 60–70 minutes after the pool opens or reopens. Once the request is mined, deposits pause until selection finishes and the next draw opens.

Every transition is permissionless. If scheduled automation is delayed, the app exposes a fallback after the grace period so a saver can advance the same proof-checked step. The keeper cannot read balances, provide the random number, or choose the winner.