Optimistic vs ZK Rollups: Onchain Governance

Fast, onchain voting: Governance proposals execute immediately after a vote passes, enabling rapid protocol upgrades (e.g., Arbitrum's DAO can deploy changes within days). This matters for protocols needing to iterate quickly on features or fee structures.

Social consensus for disputes: Relies on a fraud-proof window (typically 7 days) where challenges are resolved by a decentralized validator set. This creates a human-led "escape hatch" for catastrophic bugs, as seen in early Optimism upgrades.

Security Council control: Many implementations (Arbitrum, Optimism) use a multi-sig Security Council with emergency upgrade powers. While time-locked, this creates a temporary centralization vector.

Delayed state finality: Because transactions are only final after the challenge window, onchain governance actions (like treasury disbursements) have a built-in 7-day latency, which is suboptimal for real-time DeFi governance integrations.

Instant, verifiable execution: A valid ZK proof provides immediate state finality. Governance decisions (e.g., parameter changes in zkSync Era) are executed as soon as the proof is verified on L1, enabling sub-hour upgrade cycles.

Reduced trust assumptions: The security model depends on math, not watchdogs. This eliminates the need for a fraud-proof window or active challengers, simplifying the governance model and reducing attack surfaces.

Harder to modify circuits: Changing a ZK circuit's logic requires a new trusted setup or a transparent setup, a complex and cautious process (e.g., Starknet's upgrade to Cairo 1.0). This slows down major protocol changes compared to optimistic counterparts.

Prover centralization pressure: High-performance provers are resource-intensive, often leading to initial centralization. Governance must actively incentivize decentralized prover networks, as seen with Polygon zkEVM's community prover program.

Speed and flexibility for protocol upgrades: Governance can enact changes without waiting for complex proof systems. This enabled Optimism's OP Stack to rapidly iterate on its Bedrock upgrade and Arbitrum's DAO to approve Stylus, a new VM, via onchain votes. This matters for protocols needing to adapt quickly to market demands or integrate new standards like ERC-4337 for account abstraction.

Governance often controls a single, privileged sequencer. This creates a centralization vector and, if abused, can lead to contentious hard forks. The Arbitrum DAO treasury dispute highlighted how large token holders can influence outcomes. This matters for applications requiring maximal credibly neutral execution and for teams wary of governance capture.

Security is enforced by cryptographic proofs, not social consensus. The upgrade logic is often part of the verifier contract, making malicious changes nearly impossible without community detection. Starknet's upgrade process requires a delay for community review, and zkSync Era's security council has time-locked powers. This matters for DeFi protocols with billions in TVL that prioritize unbreakable security guarantees over agility.

Upgrades are bottlenecked by proof system compatibility. Introducing new precompiles or VM features often requires extensive work on the proving stack (e.g., Starknet's Cairo, zkSync's Boojum). This leads to longer development cycles compared to Optimistic counterparts. This matters for developers who need immediate access to the latest EVM opcodes or experimental features.