Cross-Chain Bridge

A cross-chain bridge is a protocol that enables the transfer of cryptocurrency or data between two different blockchains. Since blockchains are isolated systems by default, bridges act as intermediaries that lock assets on one chain and issue equivalent wrapped tokens on another.

How bridges work (simplified)

1. User deposits 1 BTC into the bridge contract on Bitcoin
2. Bridge locks those BTC
3. Bridge mints 1 WBTC (Wrapped Bitcoin) on Ethereum
4. User can now use WBTC in Ethereum DeFi protocols
5. To reverse: burn WBTC → receive BTC back

Common use cases for miners

• Moving mined coins from one network to a more liquid exchange
• Converting to stablecoins on a cheaper network for storage
• Accessing DeFi protocols on other chains with mined assets

Bridge risks

Bridges are among the most frequently hacked components in crypto:

• Smart contract bugs — the bridge contract holds large amounts; any vulnerability is a target
• Centralized custody risk — some bridges rely on trusted custodians
• Chain reorganization risk — a reorg on the source chain can cause inconsistencies

Major bridge hacks have resulted in losses of hundreds of millions of dollars.

See also

• Blockchain
• BNB Smart Chain
• BEP-20
• Token