Bitcoin

On Bitcoin, users interact with Multisigs (operated by a decentralsed network of validators and verifiers) to lock assets to be bridged ("source asset"), and on L2s to receive the L2 asset ("destination asset").

Additionally, users on Bitcoin may provide additional data (OP_RETURN) to trigger certain smart contract interaction on their behalf automatically by XLink.

Multisigs are Bitcoin wallets that are operated by multiple signers. In contrast to a typicall wallet requiring just one party to sign a transaction, a multisig requires multiple parties or signers to sign a transaction.