Core engineering and protocols for Alternative Mempool DDoS Protection.
Standard Ethereum mempool nodes can quickly verify classical transactions by checking nonce and balance. However, UserOperations execute arbitrary smart contract code during validation. If a smart contract checked external state (like a Uniswap price or block timestamp) that changed before block inclusion, the transaction could fail on-chain, causing the bundler to lose money.
PQCAA rigorously enforces the ERC-4337 validation sandbox rules: during the validation phase, smart accounts are forbidden from using environmental opcodes and cannot access storage belonging to other contracts. This mathematical isolation guarantees that if a UserOperation simulated successfully off-chain, it is guaranteed to execute and pay gas on-chain.