What cross-chain signing means for exchange users

Cross-chain signing lets a wallet approve a transaction on one network that can move or swap assets for use on another. If you use a centralised exchange account, the exchange usually handles the on-chain signing when you withdraw; with a self-custody wallet, you approve the transaction yourself. Knowing which setup you are using helps you understand what a prompt can and cannot do.

What does a cross-chain signature approve?

A signature is your wallet’s approval for a specific action, such as sending tokens or allowing a contract to use them. A bridge route may involve more than one action: for example, a token approval followed by a deposit into a bridge contract. Read each wallet prompt separately. A signature can authorise an action, but it does not by itself prove that the transfer has finished.

How do assets move between networks?

A bridge connects separate blockchains, which keep their own transaction records. Some routes lock an asset on the starting chain and release a corresponding asset on the destination chain; others use different mechanisms. A route may also include a swap, which exchanges one token for another, or a relayer, which submits a step on your behalf. For route choices and common execution issues, the fuller guide to bungee bridge explains the details. More steps can mean more fees and more places for a transfer to be delayed or fail.

What should you check before signing?

Check the key details in the route and wallet prompt before approving:

• Starting network: Make sure your wallet is on the network holding the assets.
• Destination: Check the destination network and address; a correct address on the wrong network may not receive the asset you expect.
• Token and amount: Confirm what you are sending and what the route says you will receive.
• Approval and fees: Check whether the prompt is for a token allowance or a transfer, and review the displayed fees.

For most beginners, the clearest route is one that shows the starting asset, destination asset, networks and fees before you approve. If a prompt does not match the action you intended, stop and check the route details.