I've grown increasingly convinced that Ethereum's Rollup future lies in a hybrid approach combining ZK and Optimistic methodologies. This article outlines my vision for this architecture and why it represents the most promising path forward.
Disclosure: While my expertise leans toward Optimistic Rollups (specifically Optimism), I welcome corrections from ZK specialists to refine this perspective.
Understanding the Foundations
Optimistic Rollup: The Bedrock Approach
Modern Optimistic Rollups like Optimism's Bedrock architecture achieve maximum Ethereum compatibility through EVM equivalence. This means:
- Running execution clients nearly identical to Ethereum's
- Leveraging Ethereum's consensus/execution separation model
- Processing transactions in deterministic L2 sequences
The critical innovation? State commitment verification:
- Rollup operators publish state commitments to Ethereum
- Validity gets enforced through fraud proofs (challenge games)
- MIPS-based architectures simplify on-chain verification
👉 Why MIPS simplifies Rollup verification
Key advantage: This approach provides bidirectional asset bridging while maintaining EVM equivalence.
Transitioning to ZK Rollup
The fundamental insight: Any Optimistic Rollup can gradually evolve into a ZK Rollup by:
- Building ZK circuits for the underlying VM (e.g., MIPS)
- Gradually replacing fraud proofs with validity proofs
- Maintaining compatibility during transition
Comparative Advantages:
| Feature | zkEVM | zkMIPS/zkVM |
|-----------------------|----------------|-----------------|
| Target Stability | EVM changes | Fixed ISA |
| Flexibility | Low | High |
| Optimization Surface | Limited | Extensive |
| Proof Complexity | High | Higher |Why Hybrid Rollups Work
Technical Superiority
- Simpler Verification
MIPS' static instruction set eliminates circuit redesigns with each EVM update. - Future-Proof Flexibility
Client modifications don't require circuit updates, enabling continuous L2 improvements. Progressive Optimization
Proof times start long but improve through:- ASIC/FPGA acceleration
- Hardware specialization
- Algorithmic breakthroughs
👉 How hardware accelerates ZK proofs
Practical Advantages
- Parallel Development: Teams can enhance core protocols while optimizing proof systems
- Smooth Transition: Run both proof systems during optimization phase
- Resource Efficiency: Focus engineering efforts on stable targets
Addressing Challenges
Proof Time Considerations
Initial constraints:
- Each EVM opcode → Multiple MIPS instructions
- Increased constraint counts → Longer proofs
Mitigation strategies:
- Dynamic gas pricing reflecting proof costs
- Gradual fraud proof phase-out as ZK proofs accelerate
- Hybrid operation during optimization
Critical insight: Web2-scale hardware optimization can dramatically reduce proof times over time.
FAQs
Why not build pure ZK Rollups now?
Existing Optimistic ecosystems offer immediate functionality while ZK infrastructure matures. The hybrid model provides continuity.
Won't proof times remain impractical?
Specialized hardware (ASICs/FPGAs) and algorithmic advances are rapidly closing this gap. MIPS' stability enables unprecedented optimization.
How does this affect dApp developers?
Minimal changes required. Gas adjustments may be needed to account for proof costs, but core functionality remains consistent.
Conclusion
The hybrid Rollup approach delivers:
- Short-term: Fully functional Optimistic systems
- Medium-term: Progressive ZK integration
- Long-term: Pure ZK efficiency
By leveraging zkVM architectures like zkMIPS, we can build scaling solutions that combine Ethereum's security with long-term sustainability - making this the most viable path forward for Ethereum scaling.