ZK-NFC Wallets

Tap-to-Pay Without a Trace

At the heart of UmbraPayOS lies the ZK-NFC Wallet, a breakthrough in how devices communicate and transact. When two users — or a user and a merchant — bring their devices close, UmbraPayOS establishes a zero-knowledge handshake using NFC. Instead of exchanging wallet addresses or signing public transactions, the two devices exchange ephemeral cryptographic proofs.

This means:

• The payer’s wallet address is never revealed.

• The transaction amount is encoded and verifiable without being exposed.

• The recipient only receives a proof of payment, not the payer’s identity.

Each payment is represented by a temporary ZK proof, which confirms that:

1. The sender owns sufficient funds.

2. The transfer is valid under network consensus rules.

3. No double-spend or fraudulent behavior has occurred.

These proofs are locally verified and stored, allowing payments to happen instantly, offline, and privately. Later, when the devices reconnect, the proofs are synced through the x402 bridge layer, finalizing them on-chain.

In short, ZK-NFC wallets make crypto behave like physical cash — instant, final, and anonymous, but cryptographically secure.