What Is a Bridge?
A bridge moves value between blockchains that cannot talk to each other natively. Bitcoin cannot run on Ethereum and ETH cannot live on Solana, so bridges lock an asset on one side and issue a matching representation on the other. Essential infrastructure, and historically the single most exploited category in crypto.
How It Actually Works
- Lock and mint: deposit ETH into the bridge contract on Ethereum; a wrapped version appears on the destination chain. Burning the wrapped token later unlocks the original.
- Liquidity networks: pools on both sides swap you directly, faster but bounded by pool depth.
- Either way, some mechanism, a contract, a validator set, a committee of signers, guards the locked side. That guard is the product, and the target.
Why Bridges Get Hacked
A bridge is a vault with a promise attached: every wrapped token is backed by a locked original. Compromise the vault's guard, forge messages, steal signer keys, exploit the contract, and you mint unbacked tokens or drain the locked side. The largest thefts in crypto history, hundreds of millions per incident in 2022's worst cases, were bridge exploits. When the backing evaporates, holders of the wrapped asset are left holding an IOU from a crime scene.
Risks and Common Mistakes
- Leaving size parked in wrapped assets from small bridges. The wrap is only as good as its guard, forever.
- Bridging through whatever a random site suggests. Prefer official chain bridges and long-established routes; check what secures the one you use.
- Fake bridge front-ends, a classic phishing lure. Bookmark real URLs.
- Forgetting destination gas: arriving on a new chain with tokens but no native coin to move them.
When It Matters
Any multi-chain life: reaching an L2, chasing an asset on another network, or exiting one. Bridge with intention, in sane sizes, and do not linger in wrapped forms you do not need. Background on my DeFi page.
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