Introduction

The problem

On-chain transfers are fully public. If you prove you sent tokens to someone, you reveal your wallet address — and with it, your entire transaction history, balances, and every other interaction tied to that address.

There's no way to say "I transferred tokens to this address" without exposing who you are.

What Proof of Transfer does

Proof of Transfer lets you prove you made a token transfer without revealing which wallet is yours.

You generate a zero-knowledge proof that cryptographically proves your transfer exists and satisfies certain constraints — without disclosing your wallet address to anyone, including the app itself.

Third parties can independently verify these proofs by fetching their own transfer data from the blockchain, so they don't need to trust the app either.

Use cases

• Anonymous donations — Prove you donated to a cause without revealing your wallet address or exact amount to other donors.
• Raffle participation — Donate to enter a raffle. Prove you participated without revealing who you are or how much you sent.
• Gift verification — Friends send tokens to a recipient for a birthday. Each can prove they contributed without revealing their wallet to the group.
• Compliance attestations — Prove a transfer happened between two parties without exposing the sender's full on-chain identity.

How it works

1. Someone creates a claim — a set of constraints describing transfers (token, counterparty, chain, time range, amount, count)
2. The app fetches matching transfers from the blockchain and builds a cryptographic merkle tree
3. Anyone who made a matching transfer can generate a ZK proof that they participated — without revealing their address
4. Third parties can verify proofs by independently fetching transfer data, without trusting the app

No wallet addresses are stored. Identity is based on nullifiers — anonymous identifiers derived from your wallet signature. Different claims produce different nullifiers, so your activity can't be linked across claims.

Supported tokens and chains

Token types: ERC-20, ERC-721, ERC-1155

Chains: Ethereum, Optimism, BNB Chain, Polygon, Base, Arbitrum, Scroll