Proof of Ownership

Proof of ownership

Prove the wallet is yours. Keep the key where it is.

Sign and verify Bitcoin, Ethereum, Solana, XRP and Cardano messages in the browser. No server, no transaction, no fee.

How it works

Signing proves control

Your wallet signs the message with your private key. The key never leaves the wallet — the site only receives the resulting signature. Nothing is broadcast to a blockchain, so there is no gas fee and no transaction.

Verification is pure maths

Checking a signature needs only the address, the message and the signature. It happens in your browser with no wallet connection and no network request, so you can verify a proof offline or from a downloaded copy of this page.

Nothing is stored

There is no backend, no database and no analytics. Shareable links keep the proof in the URL fragment, which browsers never transmit to a server.

Why it matters

Regulation

Proving control of a wallet is now a regulatory requirement, not a technical curiosity. In the EU, MiCA sets the licensing framework for crypto-asset service providers, while the Transfer of Funds Regulation governs what happens when those providers deal with self-hosted wallets — requiring verification of customer control for transfers above €1,000. Comparable rules apply in over 70 jurisdictions under FATF Recommendation 16.

Compliance

If an exchange has ever asked you to prove you own an address before releasing a withdrawal, this is what they meant. The requirement applies to deposits and withdrawals alike, and a cryptographic ownership proof is one of the accepted methods.

Independence

Signing a message is entirely off-chain: no transaction, no network fee, no funds in motion — unlike a test transfer, which costs money, takes time, and leaves a permanent public trace. You prove control of the key without ever exposing it, and without waiting for a block.

MiCA Compliant Crypto Exchanges

Kraken

Crypto-Asset Service Provider (CASP) license issued by the Central Bank of Ireland (CBI).

Coinbase

Crypto-Asset Service Provider (CASP) license issued by Luxembourg’s Commission de Surveillance du Secteur Financier (CSSF).

Bybit

Crypto-Asset Service Provider (CASP) license from the Austrian Financial Market Authority (FMA).

MiCA Compliant Crypto Banks

Revolut

Crypto services are powered by a distinct, specialized legal entity called Revolut Digital Assets Europe Ltd, Crypto-Asset Service Provider (CASP) license issued by the Cyprus Securities and Exchange Commission.

BBVA

BBVA’s MiCA compliance and crypto services in Spain were approved by the Comisión Nacional del Mercado de Valores (CNMV), Spain’s national securities market regulator.

Bison Bank

Banco de Portugal issued Bison Bank its MiCA CASP license, making it the first traditional bank in Portugal authorized to operate directly under Europe’s unified crypto framework.

Support the project

This tool was built by a member of the crypto community, for the community. It is provided free of charge, without tracking or registration and it will remain so. The source code is open and may be freely inspected, forked, and self-hosted by anyone at request.

The project has no institutional backing and generates no revenue. Contributions from users are entirely voluntary and are used to cover domain registration, development time, and the ongoing work of extending support to additional blockchains and signing standards.

If this tool has been useful to you, a donation to any of the addresses below is genuinely appreciated. Contributions in code, issue reports, and translations are equally welcome through the project repository. Donations are voluntary, non-refundable, and confer no entitlement, service obligation, warranty, or commercial relationship of any kind.

Copyright © 2026 Daedalus Labs

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