Bridge
Last Updated: October 30, 2026
Quick Answer: A bridge is a protocol that connects two blockchains so tokens, messages or data can move between them. Most bridges lock or burn a token on the source chain and mint an equivalent token on the destination chain. Bridges are heavily used, carrying about $2.78 billion in a single day on October 30, 2026, according to L2BEAT, but they are also among the most attacked parts of crypto.
Key Takeaways
- ethereum.org puts it simply: “Bridges exist to connect blockchain networks,” which cannot otherwise read each other’s data
- The main methods are lock and mint, burn and mint and atomic swaps
- Trusted bridges rely on outside validators or custodians; trustless bridges add no trust assumptions beyond the blockchains themselves
- USDC was the most bridged token, at about $2.14 billion of $2.78 billion in 24 hour volume on October 30, 2026, according to L2BEAT
- DefiLlama counted about $3.3 billion stolen from bridges in total as of October 30, 2026
How a Blockchain Bridge Works
Blockchains are isolated by design. Ethereum cannot see a balance on Solana, and Bitcoin cannot check a transaction on Base. A bridge fills that gap by watching one chain and acting on another. ethereum.org describes three ways to move value:
- Lock and mint: you lock a token in a contract on the source chain, and the bridge mints a wrapped version on the destination chain. Burning the wrapped token later unlocks the original.
- Burn and mint: the token is destroyed on the source chain and freshly issued on the destination chain. Circle’s Cross-Chain Transfer Protocol (CCTP) “natively transfers USDC across blockchains using burn-and-mint,” according to Circle.
- Atomic swaps: you trade your asset on one chain for another party’s asset on the other chain, with no wrapped token involved.
The hard part is verification: how does the destination chain know the deposit really happened? That question separates the two main security models.
| Model | Who confirms transfers | Trade off |
|---|---|---|
| Trusted (externally verified) | A multisig federation, an MPC group or an oracle network | Faster and cheaper, but users must trust the verifiers not to collude or be hacked |
| Trustless | The connected blockchains themselves, through smart contracts and proofs | No new trust assumptions, but usually slower and harder to build |
Types of Bridges and Examples
ethereum.org groups bridges by design:
- Native bridges, built by a network to bring in liquidity, such as the Arbitrum Bridge, the Polygon PoS Bridge and the Optimism Gateway. Layer 2 rollups use such bridges to hold assets on Ethereum; L2BEAT listed Base at about $15.09 billion and Arbitrum One at about $9.70 billion in total value secured on October 30, 2026.
- Validator or oracle based bridges, which depend on an external set of validators, such as Across.
- Generalized message passing bridges, which move data and contract calls as well as tokens, such as Axelar and LayerZero.
- Liquidity networks, which mainly swap assets between pools on each chain, such as Connext and Hop.
On October 30, 2026, L2BEAT reported about 128,870 transfers across 163 active routes in the previous 24 hours. Its top protocol was Circle’s CCTP v2 at about $1.27 billion, and Ethereum was the top chain, with 45.6% of volume.
Risks and Common Misconceptions
“Bridging is as safe as holding the token on its home chain.” It is not. A wrapped token is only worth what the bridge can redeem it for. ethereum.org lists smart contract risk, counterparty risk with trusted designs and systemic risk from wrapped assets, and notes that bridges account for “the top three biggest hacks in DeFi,” citing the rekt.news leaderboard.
Major incidents. The FBI has attributed the theft of “$620 million in Ethereum reported on March 29” to North Korea’s Lazarus Group and APT38; that theft, in 2022, hit the Ronin bridge used by the game Axie Infinity, according to news reports at the time. ethereum.org also cites the Wormhole bridge exploit on Solana as an example of smart contract risk. Attacks continue: DefiLlama’s hack database lists the AFX Bridge ($24.15 million, July 22, 2026, attributed to a private key compromise) and the Verus-Ethereum Bridge ($7.53 million, July 22, 2026, a bridge verification bypass), among others. DefiLlama’s running total for bridge hacks was about $3.304 billion on October 30, 2026.
“A bridge with a big brand cannot fail.” The weak point is often the keys of a small validator group or a single bug in a smart contract. Checking who verifies transfers, and how many keys an attacker would need, matters more than the brand.
Practical tips. Use the official bridge address from the project’s own site, start with a small test amount, and check that the destination wallet supports the network. Bridging also costs gas on both chains.
Related Terms
Frequently Asked Questions
What is a crypto bridge in simple terms?
A crypto bridge is a service that moves tokens or data from one blockchain to another. Since blockchains cannot read each other directly, the bridge locks or burns your token on one chain and releases or creates a matching token on the other. People use bridges to bring funds to cheaper networks, reach DeFi apps on another chain, or move stablecoins.
What is a wrapped token?
A wrapped token is a representation of an asset issued on a different blockchain, usually created by a bridge after the original asset is locked. Wrapped bitcoin on Ethereum is a common example. Its value depends on the bridge or custodian holding the original. If that bridge is hacked or fails, the wrapped token can lose its link to the underlying asset.
Are crypto bridges safe?
Bridges carry extra risk because they hold large pools of locked assets and depend on smart contracts or a group of validators. DefiLlama counted about $3.3 billion stolen from bridges in total as of October 30, 2026, and ethereum.org notes that bridges account for the three biggest hacks in DeFi. Trustless designs and official native bridges reduce, but do not remove, this risk.
How long does bridging take?
It depends on the bridge and the chains involved. Liquidity network bridges and fast messaging protocols often complete transfers within minutes. Withdrawing from an optimistic rollup through its native bridge can take about a week, because the design allows time to challenge invalid transactions. Each bridge interface usually shows an estimated time and fee before you confirm the transfer.
What is the difference between a bridge and an exchange?
An exchange swaps one asset for another, often on the same blockchain or within the exchange’s own books. A bridge moves the same asset, or a representation of it, from one blockchain to another. Some apps combine both steps, swapping and bridging in one transaction, but under the hood they still rely on a bridge to cross between chains.
Data sources: ethereum.org bridges documentation (page updated April 3, 2026), L2BEAT bridges and scaling summaries (read October 30, 2026), Circle CCTP documentation, DefiLlama hacks database (October 30, 2026), FBI statement on DPRK attribution (2022).