Confidential dollars

Your balance on Raycash is held as a confidential stablecoin — today that's cUSDC, the confidential form of USDC, backed 1:1. Over time we'll support more stablecoins. What's different is not the value. What's different is who can see your balance onchain.

The problem with non-private stablecoins

USDC, USDT, and every other standard ERC-20 stablecoin publish your balance to the world. Any block explorer — Etherscan, Arkham, Nansen, a chain-analytics firm on contract to law enforcement — can look up an address and see exactly how much it holds, and the amount of every transfer it has ever made.

That's a much weaker privacy model than a bank account, where your balance is private to you and the bank.

What a confidential stablecoin does differently

Confidential stablecoins on Raycash store balances as encrypted numbers on the Ethereum chain. The encryption uses advanced cryptography that lets a smart contract do arithmetic on encrypted values without ever decrypting them.

• Your balance onchain is a ciphertext. Unauthorized third parties cannot read it.
• A transfer moves an encrypted amount. The amount never becomes public onchain.
• The smart contract can still enforce "is the sender's balance big enough?" — it just does that on encrypted numbers.

The result is bank-level privacy: your balance and amounts are hidden from third parties (validators, explorers, chain-analytics firms, other users). Raycash itself, like a bank, sees them — the amounts are encrypted onchain but are transmitted to us through the Raycash API when you use the app, which is how we run compliance, support, and card settlement.

If you want the cryptographic deep dive, see Security → FHE & encryption.

How a transfer works, from your side

You open the app, tap send, choose an amount, confirm. That's it. Under the hood:

1. The amount is encrypted on your device.
2. A transaction goes to chain that says "move this encrypted amount from A to B."
3. The chain updates both balances using encrypted arithmetic. Outside observers cannot tell how much moved.

The recipient's balance goes up. Yours goes down. Neither number becomes public onchain.

When you withdraw onchain

If you want to move funds out as a cleartext stablecoin, the amount becomes public at that moment, because the cleartext form is public. That's the tradeoff — you're leaving the confidential system.

You can always withdraw. No hook, no KYC revocation, no operator decision can block your exit — see Compliance.

Deep dive

• Protocol → Confidential ERC-20 — the ERC-7984 standard
• Protocol → Key concepts — two-phase operations and hooks
• Security → FHE & encryption — what the encryption actually guarantees