What is a Bridge?

Blockchain bridges are protocols that enable the transfer of assets and information between otherwise isolated blockchain networks, solving the critical interoperability challenge by allowing users to move tokens, data, and instructions across different ecosystems without requiring exchanges or third-party services.

These systems typically work by locking assets on the source chain and minting equivalent representations on the destination chain (or burning and releasing for the reverse direction), maintaining a verifiable connection between the original assets and their wrapped counterparts across different blockchain environments.

Bridges vary significantly in their security models, from trusted or federated systems relying on a defined set of validators to trustless bridges that use cryptographic proofs to verify cross-chain transactions, with each approach making different tradeoffs between security, speed, cost, and complexity.

By connecting diverse blockchain ecosystems, bridges dramatically expand the utility of individual networks, allowing users to access applications, yields, and services across the entire decentralized landscape while leveraging the unique strengths of each connected blockchain.

Despite their critical importance to the blockchain ecosystem, bridges represent significant security challenges and have been targets for some of the largest hacks in cryptocurrency history, highlighting the ongoing technical challenges of securely connecting systems with different consensus mechanisms, finality guarantees, and security assumptions.