Most blockchains operate independently, with their own validators, rules, and data formats, and have no built-in way to read or verify what's happening on another chain. A bridge solves this by connecting two networks, typically by locking or burning a token on the source chain and minting an equivalent, representative version of that token on the destination chain. When the process is reversed, the representative token is burned and the original is unlocked. This lets users move value across chains, such as taking an asset native to one blockchain and using it within an application on a completely different one.
Bridges are widely used because they let users access liquidity, applications, or lower fees on another chain without giving up exposure to their original asset. However, bridges have historically been one of the most frequent targets for exploits in crypto, because they often concentrate large amounts of locked funds in a single smart contract or set of validators. The security model varies significantly between bridges; some rely on a small trusted group of validators, while others use broader decentralised verification, so the trust assumptions of a specific bridge matter. A bridged or wrapped token is generally only as reliable as the bridge that backs it.
Key takeaways
- A cross-chain bridge allows assets or data to move between separate, otherwise incompatible blockchains.
- Bridges commonly work by locking or burning tokens on one chain while minting a representative version on another.
- Bridges have historically been a frequent target for exploits, so a bridge's specific security design and track record matter before using it.
Cross-Chain Bridge — frequently asked questions
Why can't blockchains communicate with each other directly?
Most blockchains are independent networks with their own validators, rules, and data formats, so they have no built-in way to read or verify another chain's state without a bridge or similar interoperability protocol.
Is a bridged token the same as the original asset?
Not exactly. A bridged token is usually a wrapped or representative version backed by the original asset locked elsewhere, and its value depends entirely on the bridge continuing to hold and honour that backing.
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