Glossary · Infrastructure

What is Bridge?

A bridge moves assets between blockchains. The canonical pattern locks or burns the asset on the source chain and mints or unlocks a representation on the destination, with a set of validators attesting the transfer.

Bridges concentrate risk: the locked collateral is a honeypot, and history's largest exploits are bridge exploits. The alternative (swapping through liquidity on each chain, so no pooled custody exists) trades some price impact for the removal of that honeypot.

How Bridge works

A bridge moves assets between chains by locking or burning on one side and minting or unlocking a representation on the other, with some mechanism attesting that the two sides stay in step. Validators, multisigs, or light-client proofs play the attester role, and the locked pool on the source chain is the value backing every representation in circulation.

That pool is also the problem. Bridge history is the industry's grave ledger: the largest exploits were nearly all breaks of the attestation or custody layer, not of the chains. Value concentrated in one contract, guarded by a small set of signers, is the exact shape attackers look for.

The alternative that U.CASH favors where possible is liquidity-based movement: swap through pools on each chain, or between a token's native forms, so no pooled custody exists to attack. Where a bridge is unavoidable, the diligence items are the attester set, its size and independence, and the limits imposed per transfer.

Bridge in practice

A token with native deployments on two chains moves between them as a swap between forms: sell one, buy the other, value crossing through liquidity. A wrapped-asset bridge instead holds the original in a pool and mints representations, concentrating risk in the custodian.

Bridge on U.CASH

Cross-chain movement on U.CASH routes through the swap engine's liquidity-first paths where forms exist, so value moves between a token's deployments without a pooled bridge holding it.

Merchants should care which pattern moves their money. Settlement that routes through liquidity inherits market risk priced in the quote; settlement through a pooled bridge inherits custodian risk that prices in only when it fails. Asset pages state which forms are native where, which determines the pattern. The decision rule that falls out of the history: prefer native forms and liquidity paths whenever the asset offers them, and treat an unavoidable bridge as a short exposure with a size limit, not as settled infrastructure. The chain of forms each asset supports is on its page precisely so this rule can be applied without guesswork.

Related infrastructure terms

DEX routingCross-chain swapGas fees

See also

Guide: swap across chainsCross-chain swap

Bridge: FAQ

Is bridging the same as swapping?
No. A swap trades through liquidity and prices the move; a bridge custodies on one side and represents on the other. Where a token has native forms on both chains, a swap between forms needs no bridge at all.
Why are bridges risky?
Because they pool. The locked collateral on the source chain is a single target holding everyone's value: the pattern behind most of the largest exploits in the industry's history.
Are all cross-chain movements bridges?
No. Swapping between a token's native forms through liquidity is not bridging, and it is preferred exactly because it avoids pooled custody. Bridging properly means the lock-and-mint pattern.
Why are bridges hacked so often?
Concentration. Locked value plus a small attester set is a honeypot with a manageable attack surface. The exploits broke the attestation layer, not the underlying chains.
How do I know which pattern a transfer uses?
The quote tells you: a routed swap shows hops and pools; a bridge shows a lock-and-mint flow with wait times. U.CASH defaults to liquidity paths where forms exist.
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