Ethereum Foundation publishes: Restructuring the division of labor between L1 and L2, jointly building the ultimate Ethereum ecosystem

Original Title: How L1 and L2s can build the strongest possible Ethereum

Original Authors: Josh Rudolf, Julian Ma, Josh Stark, Ethereum Foundation

Original Compilation: Chopper, Foresight News

The ultimate goal of the Ethereum Foundation's Platform team is to promote Ethereum as a unified collaborative system for scalable expansion, allowing all users to use it with peace of mind.

This article aims to share our views on the relationship between L1 and L2, explain the role of each layer, and how we (as an ecosystem) can leverage the advantages of L1 and L2 to create the most attractive platform for all users.

Some of this content is already clear, while others need to be validated through ongoing experimentation and iteration with the community and users.

TL;DR

Goal: All individual and institutional users should have clear pathways to utilize, expand, and benefit from the core attributes provided by Ethereum.

The best way to achieve this goal is to fully leverage the unique features of each layer, strengthen Ethereum's core attributes, and release meaningful value for end users through these attributes.

As the Ethereum ecosystem develops, the roles of each layer also evolve:

• In the past: The primary mission of L2 was to assist Ethereum in scaling, followed by providing differentiated and customized spaces. Scalability was key.

• Today: The primary mission of L2 is to achieve scalability while providing differentiated features, services, customized solutions, marketing strategies, and control areas. Currently, the biggest driving force lies in differentiation, control, and innovation.

• L1 as a truly permissionless and highly flexible global settlement, shared state, liquidity, and DeFi hub. A powerful, scalable L1 layer that does not compromise on CROPS (Censorship Resistance, Open Source, Privacy, and Security) provides a better foundation for L2 layers.

• L2 provides valuable new features, customization, and control to develop its own on-chain economy while extending Ethereum's core attributes to more users. A strong L2 network reinforces the Ethereum ecosystem and its core.

• L2 covers all aspects, establishing differentiated binding relationships with L1 based on its own needs:

  • Those L2s seeking the closest integration with L1 should strive for synchronous composability, full interoperability, shared liquidity, and mechanisms like native Rollups.

  • L2s with various business models or technical expertise will continue to play important roles in the ecosystem, providing exclusive capabilities that L1 cannot cover.

The Ethereum Foundation (EF) will continue to develop underlying technologies to help L2 seamlessly extend L1's native features, securely bridging cross-layer and cross-chain liquidity and asset interoperability; at the same time, requiring L2 to be open and transparent, clearly disclosing its security attributes and verification standards.

In short, both sides play important roles, and their words and actions must align.

Introduction

In the past five years, a large L2 ecosystem has emerged around Ethereum L1. Various L2s inherit different native features of Ethereum: some fully replicate decentralized architectures (like Stage 2 Rollup), some inherit partial security features (like Validium, Prividium), and some only comply with the general EVM standard (not L2).

Many chains are still in development, typically starting from independent chains and gradually integrating deeply into the Ethereum L1 ecosystem. It is time for the Ethereum Foundation (EF) and the broader Ethereum ecosystem to update our understanding of the relationship between L1 and L2 networks. The last update could be said to have occurred five years ago when the Rollup-centric roadmap was first proposed as a means to scale Ethereum.

Since then, significant changes have occurred. The technology enabling L2 layers to share Ethereum's security and liquidity and to interoperate with it has matured; L2's differentiated competitiveness and user value have become increasingly prominent; L2 has grown and nurtured independent community ecosystems; and the scaling roadmap for L1 has also evolved and become clearer.

The Ethereum ecosystem needs to face these changes and learn from past successes and failures.

In recent months, the future development direction of the relationship between Ethereum L1 and L2 has gradually become clearer:

• A thriving Ethereum ecosystem must be built on a strong L1 foundation.

• Ethereum L1 will achieve orders of magnitude scaling while maintaining the highest levels of security and decentralization, continuing to serve as the core of the on-chain economy and the center of DeFi.

• In the future, there will be an ecosystem composed of independent and interoperable L2 chains, which will provide a higher degree of customization, control, and functionality that L1 chains cannot offer. These L2 chains choose to root themselves in the Ethereum ecosystem because it is the best choice for their users, communities, or enterprises.

• L2 chains will both compete and collaborate to provide a variety of specialized block space, services, and assets.

This article aims to explain in more detail the symbiotic vision of L1 and L2 and to establish a mutually reinforcing relationship between Ethereum L1 and any chain that wishes to root itself and become part of the ecosystem.

What roles do L1 and L2 play, and how do they work together?

Ethereum L1 is the world's leading programmable blockchain, unmatched by any other blockchain in user adoption, developer ecosystem, decentralization, resilience to risks, and underlying stability. Ethereum L1 is the core of the DeFi ecosystem, gathering the deepest liquidity across the network. Ethereum L1 now has a clear scaling path while maintaining decentralization and security. Thanks to the collective efforts of many teams within the Ethereum ecosystem, the development speed of zero-knowledge proof (ZK) technology has far exceeded expectations.

In the coming years, we will be able to increase Ethereum L1's capacity by several orders of magnitude while adhering to its core values.

At the same time, no single public chain can meet the diverse on-chain economic needs of the world. Even if Ethereum maintains its leading position in the future and enhances its scaling capacity by 1000 times, there will still be many different chains because they provide specialized and customized services that L1 cannot offer:

• Specialization for specific applications or use cases

• Non-EVM functionalities

• Additional privacy guarantees

• Pricing mechanisms or transaction inclusion logic

• Ultra-low latency or other ordering characteristics

• Extreme scaling features of L1 cannot be matched

• Specialized economies, market entry strategies, and growth methods

• Modular designs to meet compliance or other business needs

• Other improvements or innovations that can iterate and deliver faster than L1

  ......

This creates opportunities for L1 and L2 to establish a mutually beneficial relationship, allowing both to focus on complementary roles.

Why are other independent public chains willing to become Ethereum's L2?

• Low cost. Compared to independent underlying public chains, L2 replicates Ethereum's top security and decentralization at a very low threshold; building global decentralized validation nodes is costly, time-consuming, and extremely challenging. L2 can transfer this responsibility to Ethereum L1, paying as needed without incurring high fixed setup costs.

• Users and developers. Achieving interoperability with the largest L1 and L2 cluster in the network allows access to more users and developers; with the maturity of zero-knowledge proof technology, real-time proofs, faster L1 finality, L2 settlements, and proxy infrastructure, interoperability and cross-chain user experience will accelerate development.

• Interoperability. If designed properly, L2 can securely access L1 assets and DeFi liquidity, user accounts on L1, and any services on L1, such as oracles and ENS.

• Marketing: Being part of the Ethereum ecosystem provides brand and reputation advantages, as the Ethereum ecosystem has the best reputation, security record, and regulatory recognition among all L1s.

What can Ethereum L1 gain from this? Based on our experience and discussions with stakeholders in the ecosystem, we believe positioning Ethereum L1 at the core of the growing L2 network can strengthen Ethereum and ETH's unique position in the on-chain economy:

• Create demand for ETH and provide trust-minimized, secure bridging services between ETH and other assets. ETH plays roles as a store of value, currency, and more within the Ethereum network.

• Expand Ethereum's network effects (e.g., EVM, developer education, developer tools, user guidance, and interoperability between L2 layers)

• Consolidate Ethereum's important position as the core of a multi-chain ecosystem and the main settlement and liquidity layer of the on-chain economy.

• Provide broader business expansion, growth, and marketing support for Ethereum.

• L2s help realize the core vision of the Ethereum ecosystem. They serve as distributed engines of Ethereum's core attributes (security, resilience, and stability), maximizing the number of users who derive sustainable value from Ethereum.

The Ethereum ecosystem should not take these advantages for granted. Some of these advantages are still debated within the community or require long-term theories to be validated through experimentation, measurement, and analysis. Ultimately, the relationship between L1 and L2 must be mutually beneficial to succeed. Over the past five years, this relationship has achieved many accomplishments and laid a critical foundation for the future.

What does this mean for the future development of L2?

What does this new vision mean for L2-level users, their teams, and their communities?

Here are our recommendations:

• L2 should focus on strategies that complement L1 and achieve platform differentiation. Many L2s have successfully moved toward this vision. They achieve this by innovating features, targeting specific use cases (e.g., application chains), providing new distribution methods, or adopting novel marketing strategies. This helps them create their unique communities and extend Ethereum's features to millions of new users.

• L2 should have the right to differentiate in various ways according to its own imagination. We have seen differentiation emerge in scalability, trustlessness, privacy protection, enterprise compliance, industry domains, communities, and a range of technological innovations.

• L2 can choose to extend all or part of Ethereum's attributes based on its own goals. However, they should ensure that users can easily understand the security attributes they provide and do not provide. L2s committed to minimizing trust should at least reach Stage 1 and pass the "exit" test, meaning that even in the presence of malicious actors or security committee failures, users can safely exit to L1. L2s that choose to be closest to L1 and fully inherit its attributes should develop in the following directions:

  1. Achieve Stage 2;

  2. Synchronous composability;

  3. Become native Rollups.

• L2 should continue to work on building broader interoperability and shared liquidity mechanisms to enhance the entire Ethereum ecosystem.

• L2 should continue to operate transparently, clearly communicating its respective security attributes and its relationship with the L1 security layer to the ecosystem.

What contributions is the Ethereum Foundation making to build such a world?

To realize the vision of the L1<>L2 relationship, the Ethereum Foundation is fully committed to the following efforts:

• We are dedicated to expanding both the L1 layer and blobs without sacrificing decentralization. Currently, the blob fill rate is only about 30%, indicating significant expansion potential, and we can confidently expand the blob further if needed.

• Special support for those L2s that have or wish to deepen their capabilities in privacy, security, and trustlessness.

• The Platform team led by Josh Rudolf aims to improve the overall performance of the Ethereum platform and serve as an interface between L2 and the core protocol roadmap.

• Increase liquidity for L1, making it easier for L2 to access liquidity (faster final confirmations, withdrawals, and deposits).

• Work closely with L2 teams to understand their needs and reflect them in protocol priorities while clarifying the relationship between L1 and L2. To ensure this relationship operates effectively, we need to understand what works well, what needs improvement, and collaborate. Our goal is always to clarify and strengthen the value proposition of being part of the Ethereum ecosystem.

• Invest in R&D to achieve "native Rollup" technology, which allows L1 to fully and trustlessly verify L2 chains, thus achieving synchronous composability and secure interoperability.

• We work closely with L2Beat and other organizations to monitor and verify the security features of L2. We must rigorously and honestly assess the characteristics of L2 and their degree of association with L1 security so that users and developers can make informed choices.

• Address the main drawbacks of a multi-chain ecosystem: fragmentation. We will collaborate with the ecosystem (including various chains, wallets, and infrastructure providers) to build more comprehensive interoperability solutions to address user experience and developer platform fragmentation issues. Now, with a clearer understanding of the relationship between L1 and L2, we can begin to address the fragmentation of the Ethereum narrative.

We will work together to create a global, permissionless on-chain economy and provide the best platform for all users.