Guide

Bridge Risk, In Depth: Why Cross-Chain Bridges Get Hacked

Bottom line: useful, but the most-targeted place in crypto

A bridge is a mechanism to move assets between separate blockchains (say, Ethereum and Solana). Most lock an asset on one chain and mint an equivalent wrapped token on the other. The problem: enormous value piles up in that locked store — and there's no juicier target for an attacker.

Key points

- Bridges lock assets in one place, making them prime attack targets

- Past losses include Ronin (~$624M), Wormhole (~$326M) and Nomad (~$190M)

- Bridge exploits are reported to make up a very large share of total DeFi losses

- If you must bridge: keep amounts small, time short, and stick to trusted bridges

Why bridges are risky

  1. Concentrated value: bridges lock huge sums, so one breach is catastrophic
  2. Complex code: spanning multiple chains makes the smart contracts complex and bug-prone
  3. Reliance on validators/keys: many bridges depend on a small set of validators or multisig keys — steal those and the bridge falls

Major losses that actually happened (as reported)

BridgeApprox. sizeWhen
Ronin Bridge~$624MMarch 2022
Wormhole~$326MFebruary 2022
Nomad Bridge~$190MAugust 2022

Cumulative bridge losses run into the billions of dollars, per several analytics firms (figures are approximate, per reporting/analysis).

A wrapped token's backing depends on the bridge

A wrapped token minted by a bridge (e.g. BTC on another chain) is backed by the asset the bridge locked. If the bridge is breached and the underlying is drained, that backing can be undermined.

How to protect yourself

  • Small and brief: don't park assets in a bridge; use or withdraw promptly
  • Pick proven bridges: check audits, operating history, and how past incidents were handled
  • Verify the official URL: beware fake bridges and phishing — see the scam checklist
  • Don't leave approvals: revoke token approvals when done

FAQ

Q. Should I never use a bridge? A. Not at all — moving between chains is sometimes necessary. Just treat it as "not a place to store large sums for long," and bridge small and briefly.

Q. Can you tell me which bridge is safe? A. None is "perfectly safe." Check audits, track record and decentralisation, and don't over-trust any one.

Sources

  • Chainalysis (analysis of bridge exploits): https://www.chainalysis.com/
  • Mandiant / Google Cloud, "Dissecting the Nomad Bridge Hack": https://cloud.google.com/blog/topics/threat-intelligence/dissecting-nomad-bridge-hack
  • ethereum.org, "Bridges": https://ethereum.org/en/developers/docs/bridges/

Related: how to read a block explorer and the scam checklist.

Not financial advice

This article is for information only and is not investment advice. Crypto assets are volatile and carry risks including hacking. Do your own research and only use money you can afford to lose. Based on public information as of June 2026.

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  • 暗号資産・ブロックチェーン
  • 初心者向け解説 / Beginner-friendly
  • 中立・出典重視 / Source-backed

暗号資産・ブロックチェーンの初心者向け解説を担当する編集者です。中立性と一次情報(出典)を重視し、やさしさと正確さの両立を心がけています。投資の勧誘や助言は行いません。 A crypto & blockchain editor focused on beginner-friendly, source-backed explainers. Neutral, never financial advice.

This article is informational only and is not financial, investment, or trading advice. Prices are reference snapshots and may be outdated. Always do your own research.