How do I sign messages with Trezor?

Signing Messages with Trezor: A Practical Guide

Using a Trezor hardware wallet to sign messages adds a powerful layer of identity verification and security. This process allows users to cryptographically prove ownership of a private key without exposing it. Signing is especially useful when interacting with decentralized applications, verifying digital identities, or participating in blockchain governance.

Preparing Your Trezor Device

3. Open the official Trezor Suite application at suite.trezor.io.
4. Ensure your browser supports WebUSB and that you are using Chrome, Brave, or Edge for full compatibility.
5. Confirm that your Trezor firmware is up to date to avoid any compatibility issues during message signing.

Accessing the Sign Message Feature

1. In Trezor Suite, navigate to the 'Accounts' section and select the cryptocurrency account you wish to use for signing.
2. Click on the three-dot menu next to the account and choose the “Sign & Verify” option.
3. Switch to the “Sign” tab within the message tool.
4. Enter the message you want to sign into the text field—this can be plain text, a URL, or any string of characters.
5. Select the specific address associated with your wallet that will be used to sign the message.

Completing the Signature Process

3. Physically confirm the message details on your Trezor’s screen before approving.
4. Once approved, the device generates a cryptographic signature tied to your private key.
5. The resulting signature, displayed in hexadecimal format, appears in Trezor Suite and can be copied for external use.

Verifying Signed Messages

1. To verify authenticity, paste the original message, the public address, and the signature into a compatible verification tool.
2. Verification confirms whether the message was signed by the owner of the private key linked to that address.
3. Decentralized platforms often provide built-in tools for this purpose.
4. A successful verification means the signer controls the wallet and hasn’t altered the message post-signature.
5. Never share signatures for sensitive operations unless you trust the requesting party completely.

Frequently Asked Questions

Can I sign messages offline with Trezor?Yes, advanced users can utilize tools like trezorctl via command line in an air-gapped environment. This requires manual data transfer using SD cards or QR codes, ensuring no internet-connected device touches the private keys.

Does signing a message spend cryptocurrency?No, message signing is entirely separate from transaction broadcasting. It does not involve network fees or movement of funds. It's purely a cryptographic proof of ownership.

What happens if I lose the signed message?The signature itself holds no intrinsic value beyond its intended use. You can always sign the same or a new message again using your Trezor as long as the device and recovery seed remain secure.

Are there size limits for messages I can sign?Trezor imposes practical limits based on display capacity and protocol constraints. Extremely long messages may need to be hashed first, then the hash is signed instead of the full text to maintain usability and security.