What are native rollups? Full guide to Ethereum's latest innovation

Ethereum's scaling journey has taken a significant leap forward with the emergence of native rollups, a technology that promises to enhance the blockchain's throughput while maintaining its security guarantees. As the network continues to evolve, understanding this innovation becomes crucial for developers, investors, and users alike.

Understanding Rollups: A Brief Recap

Before diving into native rollups, it's worth revisiting the rollup technology that has dominated Ethereum's layer-2 scaling landscape for the past few years.

Rollups work by processing transactions off the main Ethereum chain (layer 1) while posting transaction data and validity proofs back to the main chain. This approach allows for significantly higher transaction throughput and lower fees while inheriting the security guarantees of Ethereum's base layer. The two main types of rollups have been:

1. Optimistic Rollups: These assume transactions are valid by default and only run computation in case of challenges. Examples include Optimism and Arbitrum.

2. Zero-Knowledge (ZK) Rollups: These generate cryptographic proofs that verify the validity of all transactions. Examples include zkSync and StarkNet.

While these solutions have dramatically improved Ethereum's scalability, they still operate as separate networks with their own validators, sequencers, and technical overhead.

What Are Native Rollups?

Native rollups represent the next evolution in this technology. Unlike traditional rollups that operate as separate protocols built on top of Ethereum, native rollups are directly integrated into the Ethereum protocol itself. This integration provides several key advantages:

1. Protocol-Level Security

With native rollups, the security guarantees are no longer provided through economic incentives or game theory alone; they're built directly into Ethereum's consensus mechanism. This means that the same validators securing the main Ethereum network are also validating the rollup transactions, eliminating concerns about sequencer centralization or validator collusion that exist in some current rollup implementations.

2. Simplified User Experience

Native rollups eliminate many of the bridging complexities and user experience friction points that currently exist when moving between layer 1 and layer 2. Users can interact with native rollups using their existing Ethereum wallets without needing to switch networks or bridge assets.

3. Enhanced Interoperability

By being directly integrated into the protocol, native rollups achieve seamless interoperability with the main Ethereum network and potentially with each other. This eliminates the composability challenges that have hampered the layer-2 ecosystem, allowing for more complex cross-rollup applications.

4. Reduced Overhead

The integration at the protocol level reduces the duplicate infrastructure needed to secure separate rollup networks, potentially making the entire ecosystem more efficient and cost-effective.

How Native Rollups Work

Native rollups function through a combination of protocol-level changes to Ethereum and specialized execution environments. Here's a simplified explanation of how they work:

1. Data Availability: Transaction data is posted directly to Ethereum's data layer, but in a more compact form than regular Ethereum transactions.

2. Execution Environments: These are specialized state machines running within the Ethereum protocol that process the rollup transactions according to their specific rules.

3. Validator Consensus: Ethereum validators include the validation of rollup blocks as part of their normal consensus duties.

4. State Management: The rollup state is maintained as part of Ethereum's overall state, though with optimizations to prevent bloat of the main state trie.

5. Finality: Rollup transactions receive finality at the same time as layer-1 transactions in the block that includes their data.

The implementation involves sophisticated technical optimizations at multiple levels of the Ethereum stack, including changes to the execution layer, consensus layer, and data availability layer.

Current Development Status

Native rollups are still in the research and development phase, with implementation expected to follow the completion of other Ethereum upgrades such as Proto-Danksharding and full Danksharding, which will provide the necessary data availability scaling.

The Ethereum Foundation and various research teams are actively working on specifications for native rollups, with testnet implementations likely to appear in the next 12-18 months.

Potential Impact on the Ecosystem

The introduction of native rollups could have far-reaching implications for the Ethereum ecosystem:

For Users

• Significantly lower transaction fees without sacrificing security
• Seamless experience moving between applications regardless of which rollup they're built on
• Reduced complexity in managing assets across multiple networks

For Developers

• Simplified development process with greater composability across the ecosystem
• Access to Ethereum's security without the overhead of building on a separate rollup
• Ability to focus on application-specific optimizations rather than scaling concerns

For Existing Rollups

Current rollup projects are likely to evolve in one of several directions:

1. Migration: Some may choose to migrate to become native rollups once the technology is available.

2. Specialization: Others might focus on specific use cases or capabilities that differentiate them from native rollups.

3. Hybridization: Some might adopt a hybrid approach, utilizing aspects of native rollup technology while maintaining their unique features.

Challenges and Considerations

Despite their promise, native rollups face several challenges:

1. Implementation Complexity: Integrating rollups at the protocol level requires significant changes to Ethereum's core infrastructure.

2. Governance Questions: Decisions about which types of rollups to support natively and how parameters should be set pose governance challenges.

3. Transition Strategies: The ecosystem will need carefully designed transition strategies for existing applications and users.

4. Resource Allocation: Validators will need to allocate resources to process transactions across multiple rollups, which presents technical and economic challenges.

Conclusion

Native rollups represent a significant evolution in Ethereum's scaling approach, bringing rollup technology from an external solution to a core protocol feature. This integration promises to deliver better security, improved user experience, and greater efficiency for the entire ecosystem.

While the technology is still under development, the foundations being laid through upgrades like Proto-Danksharding are paving the way for this next phase of Ethereum's evolution. For developers and users alike, understanding native rollups now will be valuable preparation for the future of Ethereum scaling.