Firewall is developing a firewall solution for blockchain networks to prevent smart contract exploits. Unlike traditional network firewalls, which monitor incoming and outgoing transactions to identify threats using predefined security criteria, Firewall employs rollups — aggregating multiple transactions into a single batch — and "programmable transaction finalization rules" to intercept exploits before they are recorded on the blockchain. The "proof-of-exploit" consensus mechanism it is creating classifies smart contract exploits as “invalid state transitions” to be reversed.