Кроссчейн-мост
Cross-chain Bridge
A cross-chain bridge is a protocol that transfers tokens or data from one blockchain to another. The asset is locked on the source chain, and its equivalent is issued on the target chain.
Blockchains cannot directly exchange state: a transaction on one network knows nothing about balances on another. A bridge solves this with an intermediary, meaning a set of smart contracts and a mechanism for confirming events outside the network.
## How it works
Two schemes are common. Lock-and-mint: the asset is locked in a contract on the source chain, and a wrapped version is issued on the target chain. Burn-and-mint: the token is burned on one chain and created anew on another, which requires the token itself to support minting and burning. Event confirmation is handled by validators, multisig signers, or relayers, sometimes through oracles.
## Where it is used
Transfers of stablecoins and native tokens between L1 and L2, moving assets into DeFi liquidity pools, arbitrage between DEXs on different networks, and withdrawing funds from centralized exchanges to networks with lower fees.
## What it affects
The main risk is the bridge itself. A significant share of major crypto hacks have targeted bridges, because a large amount of locked funds is concentrated at a single point, such as a contract or validator keys. Other important factors include finality delays on the source chain, withdrawal limits, and how closely the wrapped token matches the original in liquidity and redemption terms.
## Common mistakes
Sending funds to a network the bridge does not support. Confusing a wrapped token with the native token. Ignoring withdrawal limits and waiting times. Trusting an unaudited bridge simply because a pool offers high yield.
FAQ
How does a cross-chain bridge differ from an exchange?
A bridge transfers an asset or its representation between networks, while an exchange swaps one asset for another within its own market. A swap on an exchange and a transfer via a bridge are often performed one after another, but they are different operations.
Is it safe to use bridges?
Safety depends on the trust model: the number of validators, audits, incident history, and limits. There are no guarantees, and even well-known bridges have been hacked, so amounts should be assessed with this risk in mind.
What is a wrapped token?
It is a representation of an asset on another network, issued by the bridge against collateral of the original. Its value matches the original as long as the bridge operates correctly and the reserve is secured.