Imagining Hybrid Rollup: Advantages, Challenges and Development Direction

As a scalability solution, Rollup has great potential in public chain expansion. However, there are still some dilemmas, such as security, degree of decentralization, user experience, and cost-effectiveness. By solving these dilemmas and establishing a sound ecosystem and standardized support, Rollup is expected to achieve wider application and development, and provide lasting support for the scalability of the public chain.

Hybrid Rollup is a useful exploration to achieve this goal. Hybrid Rollup is an innovative concept. By integrating different architectures and absorbing their advantages, Hybrid Rollup can better solve the scalability and performance problems of the public chain, and at the same time provide higher security and better user experience. privacy protection.

This Bing Ventures article will consider the dilemma Rollup faces as a scalability solution from the perspective of public chain expansion, discuss issues such as security, decentralization, user experience, and cost-effectiveness, and explore possible solutions on this basis Scenarios and prospects for Rollup.

Single Rollup Dilemma

Zero-knowledge Rollup and Optimistic Rollup are currently two mainstream Rollup architectures, but they each have obvious limitations. Optimistic Rollup needs to submit fraud proofs, and it takes up to a week for the transaction to reach finality, while zero-knowledge Rollup faces higher costs because it needs to verify the validity proof on the chain. The former has poor user experience, and the latter has poor cost-effectiveness and sustainability. The two also have different degrees of trade-offs in terms of security and decentralization. For example, optimistic Rollups have the risk of operator fraud leading to exit scams, while most zero-knowledge Rollups are centralized, and only a few operators can submit transactions and validity proofs to L1, which increases the risk of review.

The hybrid model using optimistic Rollup and zero-knowledge Rollup is expected to provide a better trade-off in terms of security and decentralization, and maintain a certain degree of decentralization while improving overall system security. And this hybrid model is also expected to provide the best possible experience for users and developers.

In addition, mass generalization of Rollup requires a healthy ecosystem that provides developers with better tools and documentation to support them in building and deploying Rollup solutions. At the same time, it is also necessary to formulate unified standards and specifications, so as to ensure the interoperability and compatibility of different Rollup schemes.

Potential Advantages of Hybrid Rollup

Hybrid Rollup, as an emerging capacity expansion solution, is expected to bring improvements in the following aspects:

First, hybrid rollups provide greater flexibility and scalability. **By constructing a ZK circuit suitable for simple machines on L2, hybrid Rollup enables the issuance of validity proofs based on optimistic Rollup, while avoiding the problem of frequent circuit updates because the target machine architecture is fixed. This flexibility enables Hybrid Rollup to adapt to different application scenarios and needs, and to scale effectively to handle large-scale transactions.

Second, Hybrid Rollup combines the advantages of optimistic and zero-knowledge proofs to provide higher security. ** Optimistic Rollup provides high-performance and low-cost transaction processing, but there are certain risks, because the verification is performed after the transaction is submitted. Zero-knowledge proof can ensure the validity and privacy of transactions, making it difficult for attackers to tamper with or steal users' assets. By combining these two mechanisms, Hybrid Rollup can provide stronger guarantees in terms of security.

In addition, hybrid rollup can also reduce the need for trust. **By using zero-knowledge proofs to prove the correct execution of transactions, Hybrid Rollup can reduce users' dependence on the honesty of validating nodes. Users only need to believe in the correctness of the ZK circuit, without the need to verify the honesty of nodes, thus reducing the user's trust requirements.

Technical Implementation Challenges of Hybrid Rollup

As an emerging expansion solution, the hybrid rollup model faces some technical implementation challenges. Here are two main challenges:

First, the process of compiling the execution layer to a simplified virtual machine can require complex engineering and research. ** This process needs to ensure that the compiled code can be executed correctly on the simplified virtual machine and is consistent with the original execution layer. In order to solve this challenge, a series of technical issues such as compiler optimization, virtual machine architecture and compatibility need to be addressed. Only if these issues are properly resolved, the hybrid Rollup model can realize its advantages of flexibility and scalability.

Second, the implementation of traceable zero-knowledge proofs may require processing a large amount of data and computation, which poses performance and scalability challenges. **The hybrid Rollup model uses zero-knowledge proof to verify the correctness of the execution trajectory, which requires the generation and verification of a large amount of proof data. In order to ensure real-time generation and verification of these traceable proofs in the actual network, the proof generation algorithm and verification algorithm need to be optimized to improve their efficiency and scalability.

In view of these difficulties, at the current level of technology, the hybrid Rollup model is more suitable for specific application scenarios and requirements. The following are the two main application scenarios that I think are more suitable:

• The first is large-scale transaction processing. Since the hybrid Rollup model provides higher flexibility and scalability by compiling the execution layer to a simplified virtual machine approach, it is more suitable for processing large-scale transactions. It can effectively batch process a large number of transactions and achieve low-latency transaction confirmation to meet the needs of large-scale transaction processing.
• Followed by apps with high privacy concerns. The hybrid Rollup model uses zero-knowledge proofs to verify execution trajectories, thereby protecting the privacy of transactions. The details of the transaction can be proven to be correct, but the actual transaction data can be kept private and only accessible to the nodes participating in the verification. This privacy protection mechanism makes the hybrid Rollup model more suitable for application scenarios that require high privacy protection, such as financial transactions or personal identity verification.

To sum up, the hybrid Rollup model faces technical implementation challenges such as compiling the execution layer, simplifying the virtual machine and traceable zero-knowledge proof. However, in the application scenarios of large-scale transaction processing and high privacy concerns, the hybrid Rollup model shows its advantages and applicability. By solving technical challenges and meeting specific needs, Hybrid Rollup is expected to play an important role in the field of scaling.

Rollup development direction in the future

Hybrid Rollup is considered to be the development direction of Rollup in the future, but its further maturity must be based on the premise of further development of the following single Rollup technology:

The first is the optimistic Rollup model. Optimistic Rollup provides higher transaction throughput and lower cost by further optimizing and improving the optimistic confirmation (finality) mechanism. This may involve innovations in more efficient state management, transaction submission, and dispute resolution mechanisms. Optimistic Rollup models have the potential to outperform Hybrid Rollup in terms of performance and cost.

The second is the zero-knowledge proof Rollup model. With the development of zero-knowledge proof technology, it will bring more efficient and faster verification process, thereby improving the performance and scalability of zero-knowledge proof Rollup, including more efficient proof construction, more compact proof size and faster verification Innovations in algorithms, etc. The zero-knowledge proof Rollup model is expected to surpass hybrid Rollup in terms of verification efficiency and performance.

We believe that the introduction of Hybrid Rollup will promote more projects and developers to participate in building the Rollup ecosystem. By providing flexibility and scalability, Hybrid Rollup opens up more opportunities for various application scenarios and industries. For example, the DeFi field can take advantage of the high performance and low cost of Hybrid Rollup to build more complex financial agreements and smart contracts. The following are some directions I am optimistic about:

1. Cross-chain interoperability: Hybrid Rollup can provide cross-chain interoperability solutions for different public chains. By using hybrid Rollup as a bridging layer, each public chain can achieve safe and efficient asset transfer and information transfer. This will promote collaboration and value flow between multiple chains, breaking down barriers between existing chains. The interoperability between Ethereum and other public chains is a potential opportunity. Through hybrid Rollup, a larger scale of seamless interaction and combination of assets on both chains can be achieved.
2. Industry Compliance and Privacy Protection: The combined features of Hybrid Rollup can provide solutions for industry compliance and privacy protection. By adopting zero-knowledge proof technology, Hybrid Rollup can ensure transaction privacy and provide verifiable transaction execution. This is especially important for areas with high demand for privacy protection, such as the RWA field and institutional users.
3. Community Governance and Consensus Mechanism Innovation: The development of Hybrid Rollup will encourage more community governance and consensus mechanism innovations. By introducing hybrid Rollup, the public chain community can achieve higher transaction throughput and lower costs while maintaining a high degree of decentralization and security. This may lead to experiments and improvements in public chain governance and consensus mechanisms to meet the needs of different DAOs.
4. Infrastructure and development tool support: With the development of hybrid Rollup, it is expected that more infrastructure and development tool support will emerge. Developers can build tools and platforms for deploying and managing hybrid Rollups, simplifying the development process and providing a better user experience. This will further drive the adoption of hybrid rollups and provide developers with more opportunities and resources.

To sum up, Hybrid Rollup is expected to bring positive trends in terms of ecosystem expansion, cross-chain interoperability, industry compliance and privacy protection, community governance and consensus mechanism innovation, as well as infrastructure and development tool support. With the continuous development of technology and applications, hybrid Rollup will further improve the scalability and practicality of L1 and L2.