What Is the Difference between a Custodial and a Trustless Bridge?

A custodial bridge relies on a centralized entity or a small group of validators (custodians) to lock and release the assets, requiring users to trust the custodians. A trustless (or decentralized) bridge uses smart contracts and cryptographic proofs to automatically and permissionlessly manage the asset locking and minting process, eliminating the need for human intermediaries and reducing counterparty risk.