Ethereum Foundation Announcement: Redefining the Roles of L1 and L2, Building the Ultimate Ethereum Ecosystem Together

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

Original author: Josh Rudolf、Julian Ma、Josh Stark, Ethereum Foundation

Original compilation: Chopper, Foresight News

The Ethereum Foundation Platform team’s ultimate goal is to scale Ethereum as a unified, coordinated system—so that every user can use it with confidence.

This article is intended to share our perspective on the relationship between L1 and L2, explain the role of each layer, and—together as an ecosystem—leverage the strengths of L1 and L2 to build the most compelling platform for all users.

Some of these ideas are already quite clear, while others still need to be validated through ongoing experimentation and iteration with the community and users.

TL;DR

Goal: All individual and institutional users should have a clear pathway to use, expand, and benefit from Ethereum’s core attributes.

The best way to achieve this goal is to fully leverage each layer’s unique capabilities—strengthening Ethereum’s core attributes—and unlock meaningful value for end users through those attributes.

As the Ethereum ecosystem evolves, the role of each layer evolves as well:

• In the past: L2’s primary mission was to help scale Ethereum, and secondarily to provide room for differentiation and customization. In that, scalability was the key.

• Today: L2’s primary mission is to provide differentiation through features, services, customization solutions, go-to-market strategies, and control—while also delivering scalability. Today, the biggest drivers are differentiation, control, and innovation.

• L1 as a truly permissionless, maximally flexible global settlement layer, shared state, liquidity, and the DeFi hub. A powerful, scalable L1 layer that does not compromise CROPS (censorship resistance, open source, privacy, and security) provides a better foundation for the L2 layer.

• L2 provides valuable new functionality, customization, and control to develop its own on-chain economy, while extending Ethereum’s core attributes to more users. A strong L2 network strengthens the Ethereum ecosystem and its center of gravity.

• L2 covers all aspects, building differentiation through relationships with L1 based on its own needs:

  • Those L2s seeking the tightest possible integration with L1 should aim for synchronous composability, full interoperability, shared liquidity, and mechanisms such as native Rollups.

  • L2s with different business models or technical expertise will continue to play important roles in the ecosystem; they will also provide exclusive capabilities that L1 cannot cover.

The Ethereum Foundation (EF) will continue to develop core underlying technologies, enabling L2 to seamlessly extend L1’s native capabilities, securely connecting cross-layer and cross-chain liquidity and asset interoperability; at the same time, it requires L2s to be open and transparent—clearly publishing their security properties and validation standards.

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

Introduction

Over the past five years, a large L2 ecosystem has emerged around Ethereum L1. Different L2s inherit different native Ethereum characteristics: some fully replicate decentralized architectures (e.g., Stage 2 Rollup), some inherit partial security properties (e.g., Validium, Prividium), and some are only compatible with the general EVM standard (not L2).

Many chains are still under development. They typically start from independent chains and gradually integrate more deeply into the Ethereum L1 ecosystem. Now is the 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, arguably, was about five years ago, when an L2-centered roadmap was first proposed as a way to scale Ethereum.

Since then, things have changed dramatically. The technologies that enable L2 to share Ethereum’s security and liquidity and interoperate with it have matured; L2’s differentiation and user value have become even more evident; L2 itself has grown and flourished, giving rise to independent community ecosystems; and L1’s scaling roadmap has evolved as well, becoming clearer.

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

Over the past few months, the future direction of the relationship between Ethereum L1 and L2 has gradually become clearer:

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

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

• In the future, an ecosystem will emerge composed of independent and interoperable L2 chains. It will provide a higher degree of customization, control, and functionality than an L1 chain can offer. These L2 chains choose to take root in the Ethereum ecosystem because the Ethereum ecosystem is the best option for their users, communities, or enterprises.

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

This article aims to explain the L1 and L2 symbiotic vision in more detail, and to lay out a path that establishes mutually reinforcing relationships between Ethereum L1 and any chain that wants to take root and become part of the ecosystem.

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

Ethereum L1 is the world’s leading programmable blockchain. In terms of user adoption, the developer ecosystem, decentralization, resilience to risks, and underlying robustness, no other blockchain can currently match it. Ethereum L1 is the core of the DeFi ecosystem, bringing together the deepest liquidity across the entire network. Ethereum L1 now has a clear scaling path, while still maintaining decentralization and security. Thanks to the combined efforts of many teams in the Ethereum ecosystem, the development speed of zero-knowledge (ZK) proof technology is far beyond expectations.

Over the next few years, we will be able to increase Ethereum L1’s capacity by several orders of magnitude while staying true to its core-value vision.

At the same time, no single monolithic blockchain can meet the global demand for a diverse on-chain economy. Even if Ethereum remains the top leader in the future and scaling capacity increases by 1000x, there will still be many different chains, because they offer specialized and customized services that L1 cannot provide:

• Specialization for specific applications or use cases

• Non-EVM functionality

• Additional privacy guarantees

• Pricing mechanisms or transaction-inclusion logic

• Ultra-low latency or other sequencing characteristics

• L1’s extreme scaling capabilities cannot be matched

• Specialized economies, go-to-market strategies, and growth methods

• Modular design to meet compliance or other business needs

• Other improvements or innovations, whose iteration and delivery speed can be faster than L1

  ……

This creates an opportunity to establish a mutually beneficial relationship between L1 and L2, allowing both sides to focus on complementary roles.

Why would other independent chains be willing to become Ethereum’s L2?

• Low cost. Compared with independent L1 base chains, L2 can replicate Ethereum’s top-tier security and decentralization with a very low barrier to entry; building a global decentralized validation node network is costly, time-consuming, and extremely difficult. L2 can shift this responsibility to Ethereum L1, pay as needed, and avoid bearing high upfront fixed setup costs.

• Users and developers. By achieving interoperability with the largest L1 and L2 clusters across the entire network, you can reach more users and developers. And because zero-knowledge proof technology, real-time proving, faster L1 finality and L2 settlement, and mature proxy infrastructure have advanced, interoperability and cross-chain user experience will accelerate

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

• Go-to-market: As part of the Ethereum ecosystem, it benefits from advantages in brand and reputation. The Ethereum ecosystem has the best reputation, security record, and regulatory recognition among all L1 networks.

What can Ethereum L1 get out of this? Based on our experience and discussions with stakeholders across the ecosystem, we believe that positioning Ethereum L1 at the core of a rapidly growing L2 network can strengthen Ethereum and ETH’s unique role in the on-chain economy:

• Create demand for ETH and provide trust-minimized, secure bridging services between ETH and other assets. ETH plays value-storage and monetary roles within the Ethereum network.

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

• Solidify Ethereum’s position as the core of a multi-chain ecosystem and as the main settlement and liquidity layer of the on-chain economy

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

• L2 helps realize the core vision of the Ethereum ecosystem. As distributed engines of Ethereum’s core attributes (security, resilience, and stability), they maximize the number of users who can capture sustainable value from Ethereum.

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

What does this mean for the future 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 a strategy that complements L1 and achieves platform differentiation. Many L2s have already successfully moved toward this vision. They do so by delivering innovative features, targeting specific use cases (e.g., application chains), offering new distribution methods, or adopting novel go-to-market strategies. This helps them build their own distinct communities and extends Ethereum’s characteristics to millions of new users.

• L2 should be empowered to differentiate itself in all kinds of ways according to its own imagination. We have already seen differentiation emerge across scalability, trustlessness, privacy protection, enterprise compliance, industry verticals, communities, and a range of technical innovations.

• L2 can choose to extend all or part of Ethereum’s attributes based on its own goals. But it should ensure that users can easily understand which security attributes it provides and which it does not. L2s committed to minimizing trust should at least reach Stage 1 and pass the “exit” tests—meaning that even if there are malicious actors or the security committee fails in its duty, users can safely exit back to L1. L2s that are closest to L1 and fully inherit its attributes should move in these directions:

  1. Reach Stage 2;

  2. Achieve synchronous composability;

  3. Become a native Rollup.

• L2 should continue to work toward building broader interoperability and shared-liquidity mechanisms, strengthening the entire Ethereum ecosystem.

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

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

To achieve the vision for the L1<>L2 relationship, the Ethereum Foundation is fully committed to the following work:

• We are dedicated to expanding L1 and blobs without sacrificing decentralization. Today, blob utilization is only around 30%, leaving significant room for expansion. If needed, we can be fully confident in expanding blobs further.

• Particularly support L2s that have or want to deepen expertise in privacy, security, and trustlessness.

• Josh Rudolf leads the Platform team, aiming to improve the overall performance of the Ethereum platform and serving as the interface between the L2 and core protocol roadmaps.

• Improve L1 liquidity so that L2 can obtain liquidity more easily (faster final confirmations, withdrawals, and deposits).

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

• Invest in R&D to enable “native Rollup” technology—an L2 chain that L1 can fully and trustlessly verify—thereby enabling synchronous composability and secure interoperability.

• We work closely with L2Beat and other institutions to monitor and verify L2 security properties together. We must evaluate L2 properties and how they relate to L1 security with rigor and honesty, so that users and developers can make informed choices.

• Address major downsides of multi-chain ecosystems: fragmentation. We will work with the ecosystem (including chains, wallet providers, and infrastructure providers) to build more complete interoperability solutions to solve the problem of fragmented user experience and developer platforms. Now that we have a clearer understanding of the relationship between L1 and L2, we can start addressing fragmentation in the Ethereum narrative.

Together, we will build a global, permissionless on-chain economy—and provide the best possible platform for all users.