⚠️ Security Models: Trusted vs Trustless
Compare bridge security trade-offs and attack vectors
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0 / 5 completed⚠️ Bridge Security Risks
Bridges are the most attacked DeFi infrastructure. Over $2.5 billion stolen from bridges in 2022 alone—more than all other DeFi hacks combined. Why? They're high-value targets (billions in locked assets), complex (multi-chain logic), and often use centralized trust assumptions (multisigs). The three catastrophic hacks—Ronin ($625M), Poly Network ($611M), Wormhole ($325M)—weren't theoretical vulnerabilities. They were real exploits that drained user funds in hours. Understanding attack vectors is critical for developers building or auditing bridge contracts, and for users deciding which bridges to trust with their assets.
🎮 Interactive: Attack Scenario Explorer
Select an attack type to see real-world exploits, how they work step-by-step, and how to prevent them. Learn from $1.6B+ in actual losses.
Validator Compromise
CriticalAttackers steal validator private keys and forge cross-chain messages
- 1Bridge secured by N-of-M multisig (e.g., 5-of-9 validators)
- 2Attacker targets validators via social engineering, phishing, or infrastructure hacks
- 3Once threshold keys obtained (5 in Ronin case), attacker can sign any message
- 4Forge withdrawal message: "Mint 173,600 ETH + 25.5M USDC to attacker address"
- 5Destination chain sees valid signatures, mints tokens without actual lock
- 6Attacker drains funds before detection (Ronin took 6 days to notice)
- ✓Hardware security modules (HSMs) for key storage
- ✓Distributed key generation (DKG) - no single party knows full key
- ✓Increase validator set size and geographic diversity
- ✓Rate limiting: Cap withdrawal amounts per hour
- ✓Multi-factor authentication and IP whitelisting for validators
- ✓Real-time monitoring and anomaly detection
Total loss of bridged funds. Ronin had to raise $150M to reimburse users.
📊 Bridge Hack Statistics (2021-2022)
5-of-9 validator keys compromised via social engineering. Attacker minted 173,600 ETH and 25.5M USDC.
Smart contract vulnerability allowing attacker to replace keeper keys. Funds returned (whitehat?).
Signature verification bypass. Attacker minted 120k WETH without backing. Jump Crypto bailout.
Merkle root validation bug. Anyone could forge withdrawal proofs. 41 attackers drained funds.
Bridges account for 69% of all DeFi hacks by value. More than hacks, rug pulls, and exploits combined.
🛡️ Defense in Depth
No single security measure prevents all attacks. Bridges need layered defenses:
- • Multi-sig with HSMs
- • Threshold signatures (BLS, FROST)
- • Zero-knowledge proofs
- • Multiple audits + formal verification
- • Bug bounties ($1M+ rewards)
- • Upgradeable with time locks
- • Bonded validators (slashing)
- • Insurance pools
- • Rate limits + daily caps
- • Real-time monitoring
- • Emergency pause mechanisms
- • Incident response playbooks
💡 User Security Best Practices
- •Test Small First: Bridge $10-50 before moving large amounts. Confirm receipt on destination.
- •Check Audits: Only use bridges audited by reputable firms (Trail of Bits, OpenZeppelin, Certora).
- •Monitor TVL Drops: Sudden TVL decrease = possible exploit. Check Twitter, Discord before bridging.
- •Diversify: Don't keep all assets on one chain via one bridge. Spread risk.
- •Understand Trust Model: 3-of-5 multisig = 3 parties control your funds. Acceptable?