A cross-chain bridge moves value between blockchains that cannot communicate directly. It does this in one of a few ways: locking tokens on one chain and minting wrapped tokens on another, burning tokens on one chain and minting the same native token on another, or using liquidity pools on both sides so you receive native tokens immediately. Each design trades off speed, cost and trust.
Key Takeaways
- Lock-and-mint: wrapped tokens backed by locked originals.
- Burn-and-mint: native tokens on each chain, issuer-controlled.
- Liquidity networks: fast, using pools on both sides.
- Rollup bridges: most trust-minimized, slow withdrawals.
Bridge Designs Compared
| Design | How it works | Speed | Trust in |
|---|---|---|---|
| Lock-and-mint | Lock on chain A, mint wrapped on chain B | Minutes | Bridge validators / custodian |
| Burn-and-mint | Burn on A, issuer mints on B | Minutes | Token issuer |
| Liquidity network | Deposit to pool on A, receive from pool on B | Seconds-minutes | Bridge contracts and relayers |
| Native rollup bridge | Messages verified by the rollup | In fast, out ~7 days | The rollup and Ethereum |
Wrapped vs Native Tokens
Lock-and-mint bridges produce wrapped tokens that depend on the locked originals staying safe. Burn-and-mint and liquidity networks usually deliver the native token. That difference matters for which apps accept the token; wrapped bitcoin is a good example, covered in what is wrapped bitcoin.
How to Pick a Bridge
- Route support: does it connect your two networks and tokens?
- Cost and time: compare total received, not just the fee.
- Token received: native or wrapped, and does your app accept it?
- Security record: audits, age, past incidents.
A bridge aggregator does this comparison per route. Common routes: bridge ETH to Arbitrum, bridge to Base, bridge ETH to Solana. An independent overview of bridge risks is maintained by L2BEAT.
