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🛑 Security Model: Exit Games & Mass Exits

Learn how users can escape compromised Plasma chains

Explore Ethereum's first Layer 2 scaling solution

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🔐 Plasma Security Model

Plasma's security relies on three pillars: fraud proofs for invalid state transitions, exit mechanisms for user protection, and data availability assumptions that users monitor the chain.

🛡️ Three Security Guarantees

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1. Fraud Proofs

If an operator includes an invalid transaction (e.g., double-spend, unauthorized transfer), anyone can submit a fraud proof to Ethereum. The operator is slashed and the block is rejected.

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2. Exit Game

Users can always withdraw their funds to Ethereum by providing a Merkle proof of their balance. Even if the operator stops producing blocks, users retain custody through exits.

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3. Watchdog Requirement

Security assumes users (or watchers) monitor the chain for fraud. If you're not watching and miss a fraud, you must trust others to catch it and challenge on your behalf.

🎮 Exit Game Simulator

Step through the complete exit process from initiation to finalization. Navigate at your own pace to understand why withdrawals take 7-14 days.

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Exit Initiated

Step 1/5

User submits exit request with Merkle proof to Plasma contract

Exit Progress20%

💡 Step through at your own pace

⏰ Why 7-14 days? The delay ensures enough time for anyone to submit fraud proofs if the exit is based on invalid state. This protects honest users from malicious withdrawals.

⚠️ Mass Exit Problem Simulator

What happens when everyone tries to exit at once? Adjust the load to see how network congestion affects exit times and costs.

Exit Queue Load25% capacity

✅ Normal Operations

Exit Delay

7 days

Gas Cost Multiplier

The Problem: Plasma exits are processed on Ethereum, which has limited throughput (~15 TPS). If thousands of users try to exit simultaneously, the exit queue becomes congested.

Consequences: During mass exits, gas wars drive costs 20-50x higher, exit delays extend beyond 2-3 weeks, and some users may be unable to exit at all if they can't afford the gas.

Mitigation: Priority queues (pay more to exit faster), staggered exits over time, and trusted fast exits through liquidity providers who advance funds.

🔐 Data Availability Challenge

Plasma's biggest limitation: users must download their transaction data to construct exit proofs. If the operator withholds data, users can't prove their balance to exit.

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Data Available

Operator publishes all transaction data. Users can download proofs and exit safely. Plasma works as intended.

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Data Withheld

Operator stops publishing data. Users can't construct Merkle proofs. Funds are stuck unless operator cooperates or users had backups.

💡 This is why rollups are preferred: Rollups post all transaction data to Ethereum, guaranteeing data availability. Plasma requires users to be online and watching, which is impractical for most users.