ENBANKED

Problem Statement

We were inspired by the 1.4 billion people around the world who remain unbanked. When we visited developing regions, we saw people struggling to access cash or financial services due to lack of ID or infrastructure. That motivated us to build a decentralized crypto-to-cash bridge using Worldcoin’s proof of personhood, enabling anyone—even without an ID—to withdraw money and participate in the economyWith this app, anyone who wants to convert crypto to cash can visit a participating local shop and complete the exchange. This project enables 1.4 billion unbanked people around the world to withdraw cash from their crypto wallets, and empowers local shop owners in towns and villages to act as decentralized banks—offering crypto-to-cash exchange services to their communities.

Solution

We let anyone in deposit funds into an on-chain vault, then hand over a QR code that – later – can be scanned inside World App to withdraw that same amount without revealing who deposited it.The anonymity comes from a Groth16 zero-knowledge proof + a small Poseidon-based Merkle tree that lives in the vault contract.Key technologies:World App (client) for smooth UX layerQR code for transferring secretsClient-side ZK proofs in the browser/WASM + Merkle tree + token vaultGroth16Verifier (generated by snarkjs) / PoseidonTricks and considerationsFor everyone use, we chose World App as most-people friendly interfaceFor super fast ZK proof in low CPU mobile, we make our Merkle tree super swallow(3 tier)