Future Prospects of Ethereum L1 zkEVM

There seems to be a common misconception that Ethereum can only be scaled through L2. This view may stem from an excessive focus on discussions around L2 Rollups, while neglecting the L1 scaling roadmap. Now that L2 has been widely understood, accepted, and adopted, it is time to correct this error. It is worth noting that Arbitrum One has become the second largest smart contract chain, after Ethereum L1.

A more serious misunderstanding is that "ETH" can only be expanded through L2. In fact, ETH as a monetary asset can be expanded in various ways, including L1, sidechains, other L1s, L2s, quasi-L2 structures like validum and optimistic chains (, and even centralized services.

Millions of ETH have been bridged to L2 and non-L2 chains, as well as non-blockchain platforms. While ETH on L1 and mature L2 provides native security guarantees, other solutions, despite possibly having different security assumptions, can still scale ETH or Ethereum assets. It is worth mentioning that Bitcoin primarily scales through centralized services, yet remains the dominant asset in the industry, indicating that asset value does not solely depend on the level of decentralization.

It is important to distinguish between ETH or Ether and the Ethereum blockchain. For example, a certain blockchain may have expanded the technology stack of Ethereum and built a bridge between ETH and ERC-20, but it may not be considered an extension of the Ethereum network.

Let's return to the question of upgrading Ethereum L1 to zkEVM. Using ZKP to scale blockchains is an old concept, possibly first discussed regarding Bitcoin. Research on ZK-SNARKing Ethereum accelerated in early 2020 with the proof of concept from several projects. In 2021, the term "zkEVM" became popular and has been used ever since. The Ethereum Foundation's privacy and scaling exploration team is the main innovator of L1-zkEVM, and later, other teams joined to contribute.

The L1 zkEVM upgrade may go through the following steps: First, test Type-2/2.5 and Type-1 zkEVM rollups in the production environment. Second, implement certain key protocol upgrades. Next, deploy the Enshrined zkEVM bridge, allowing Type-1 zkEVM deployments on top of L1, which will conduct practical testing for the code and zk circuits ultimately used for L1 zkEVM.

Once these steps are completed, the L1 execution layer will be ready for the zkEVM upgrade. Builders will sort transactions, generate proofs, and submit them to the consensus layer. Non-builder nodes only need to verify these proofs, effectively validating a large amount of TPS, including L2, L3, etc., all of which are proven by the single concise proof of the L1 zkEVM.

The enshrined zkEVM bridge may continue to exist above the L1 execution layer or be moved to the consensus layer. There may be a standard enshrined L1 rollup, as well as multiple Type-0 enshrined L2 rollups, along with traditional L2 and sovereign rollups.

It is important to note that enshrined L2 rollups have their own trade-offs. The zkEVM may be slower in the early stages, with throughput and functionality limitations, and a lower upgrade frequency. They will be fully executed by Ethereum node operators, with no independent governance. Therefore, innovation is expected to mainly occur on traditional L2s, and it is anticipated that most users will still choose to use them.

These different types of rollups and chain structures provide users with diverse options, expected to meet most of the needs of the blockchain ecosystem in the coming decades.

Of course, all of this may be superfluous, and we may not need such high throughput. A more conservative approach would be to keep L1 unchanged, and zkEVM may never be realized on L1. In any case, we are approaching the end of this decade, and future developments remain uncertain. But this vision sounds interesting and is worth looking forward to becoming a reality.