From Real-Time Proofs to Native Rollups: The Final Stage of Ethereum Scaling Driven by ZK

Author: imToken

Editor's Note: Ethereum is heading towards a new era of scalability with 10,000 TPS, and zero-knowledge proof (ZK) technology is becoming a key driving force. This article is the second in our "Ethereum 10,000 TPS Roadmap," focusing on the technical difficulties of real-time proofs, Prover's participation logic, security challenges during the L1 switch, and how "native Rollup" becomes the ultimate form of ZK scalability.

If ZK-ization is the starting point of Ethereum's technological reconstruction, then "real-time proof" and "native Rollup" are the core implementation links of this expansion revolution.

In this article, we will continue to explore in depth how to achieve 12-second ZK real-time proof on the Ethereum mainnet, what the hardware threshold and incentive mechanism are for becoming a Prover, and how native Rollup will rewrite the landscape of Ethereum L2.

01. Real-time Proof: The Key Piece of Ethereum Scaling

On Ethereum's roadmap to 10,000 TPS, there is an indispensable technological breakthrough: real-time proving.

Succinct co-founder Uma Roy explained: "Real-time proof refers to the ability to complete the ZK proof generation process for a block on the Ethereum mainnet in less than 12 seconds."

What does this mean? Once real-time proof is achieved, Ethereum will be able to incorporate its block verification logic into the protocol itself and increase the gas limit almost "arbitrarily" without sacrificing verifiability, thereby achieving massive expansion of L1 (Editor's note: The generation time of each block on the Ethereum mainnet is 12 seconds, so "real-time" means that the proof is completed within each block cycle).

However, to achieve real-time proof, zkVM technology alone is not enough, and changes to the Ethereum protocol layer are also required.

Ladislaus of the Ethereum Foundation pointed out that a key mechanism is expected to be introduced in the Glamsterdam upgrade next year - "decoupling of block verification and immediate execution", which will provide Prover (prover) with more time to generate zkEVM proof within a complete slot, thereby achieving true real-time processing.

In terms of technical implementation, Succinct has released its latest SP1 Hypercube zkVM, which can generate proofs for 93% of the 10,000 mainnet blocks in real time on a cluster of 200 GPUs.

Roy expressed confidence that they could increase this success rate to 99% by the end of the year. While some difficult blocks might still prevent proofs from being generated in a very small number of blocks, the protocol design incorporates fault-tolerance mechanisms, such as allowing for skipping such blocks and continuing with the next one.

Furthermore, Ethereum is considering reducing the block time from 12 seconds to 6 seconds (as another potential proposal for Glamsterdam), which will significantly improve user experience and transaction confirmation speed, but this also puts additional pressure on ZK Prover - for the prover, the difficulty of the task is doubled.

However, Roy is not worried. After all, the performance of ZK technology can be improved 10 times every year, so it can cope with it even if the block time is halved.

In June, Linea also announced that 100% of on-chain activities on its network are covered by ZK proofs. Although Linea's current TPS is only 2, this is not a performance limitation, but is limited by usage needs.

It is worth noting that the Linea block interval is only 2 seconds, and the ZK proof is uploaded to Ethereum L1 for verification through smart contracts. This model may be the forerunner of the "ZKization" of the future mainnet.

02. Is the hardware threshold for Ethereum ZK prover high?

Generating ZK proofs in real time requires powerful computing resources.

The Ethereum Foundation's initial technical goals for Prover are to keep hardware costs below $100,000 and power consumption below 10 kilowatts, roughly equivalent to the power consumption of a Tesla Powerwall home battery.

This number doesn’t sound “light” at all. Ethereum critic Justin Bons (founder of Cyber Capital) called it “crazy hardware requirements that far exceed Solana’s validator nodes,” but this actually confuses two completely different roles.

Ladislaus from the Ethereum Foundation's protocol coordination team pointed out that Prover and Validator have different responsibilities and should not be confused. Validators run nodes and participate in consensus, while Prover's task is to generate ZK proofs. Once the ZK proof of a transaction is correctly generated, the network only needs to verify whether the proof is correct, without the need to re-execute the transaction.

Because of this, Ladislaus expressed optimism, "As long as an honest prover who meets the hardware requirements can be found, Ethereum can continue to operate securely. We deliberately lower the threshold below the data center. Even if it is not a large institution or data center, any individual developer with technical capabilities can run Prover at home."

Currently, this $100,000 hardware configuration is only an initial goal. Ethereum Foundation researcher Sophia Gold predicts that mainstream Prover will meet the standard before the Devconnect Argentina Developer Conference in November this year.

Succinct co-founder Roy expects that by early next year, the GPU requirement can be reduced to about 16 graphics cards, and the total cost will be controlled between $10,000 and $30,000.

At the same time, Succinct has built a decentralized network consisting of "hundreds of provers" on the test network, generating millions of proofs in total.

The core logic of this system is competitive proof, that is, all Provers participate in the bidding, and a winning bidder is selected in each round to execute the zk proof. The goal is to allow participants with shorter time and lower cost to win, forming a computing power bidding mechanism.

This means that in the ZK-driven future of Ethereum, the spirit of miners will reappear in another form - except that their role has changed from calculating blocks to calculating proofs.

03. Mainnet Switching to ZK Architecture: A Highly Difficult System Migration

Switching the Ethereum L1 mainnet to a zero-knowledge proof (ZK) architecture is another technical challenge of almost the same level following the transition from proof-of-work (PoW) to proof-of-stake (PoS) in 2022. The entire process not only requires the reconstruction of the protocol layer, but also requires careful consideration of various potential edge scenarios and security risks to prevent network interruptions.

At an EthProofs conference in July, researcher Justin Drake outlined several potential risks. For example, a malicious attacker could insert a so-called "prover killer" into a block, rendering the entire network's verification mechanism ineffective. Alternatively, a sudden drop in network activity could result in insufficient transaction fees to cover the cost of generating ZK proofs, impacting network sustainability.

Ladislaus of the Ethereum Foundation's Protocol Coordination Team stated that the entire transition process could take several years, with particular attention paid to security risks. The ZK Virtual Machine (zkVM) is a complex technology still in its early stages, and various vulnerabilities are highly likely. However, as the ecosystem matures, its feasibility and robustness on Ethereum's L1 can be gradually improved through the introduction of diverse proof systems (proof diversity), improved incentive mechanisms, and formal verification.

At the same time, Ethereum also plans to fundamentally restructure its consensus layer, namely building a new structure called "Beam Chain". The goal is to be ZK-optimized and friendly from the beginning of the design. Drake even said that in the future, the entire Ethereum data verification work will be able to be completed on the CPU of an ordinary laptop.

04. Mainnet “Snarkization”: Native Rollup is coming

While the Ethereum mainnet is integrating zkEVM, another long-term vision is gradually emerging: Native Rollup.

Current Rollups (whether Optimistic or ZK type) all use an independent proof system, whose security relies on its own validator or sorter mechanism, and there are certain trust assumptions between them and the Ethereum mainnet.

The vision of "native Rollup" is completely different - by integrating zkEVM into the mainnet, Ethereum L1 validators can directly verify the state transition proof of Rollup, thereby realizing L2 that is truly verified and secured by the mainnet.

This requires adding a key code "execute precompile" to the Ethereum L1 client, allowing validators to directly verify the ZK state transfer proof generated by L2. As Ladislaus, the protocol coordinator of the Ethereum Foundation, said, "L1 validators will consume the execution proofs of these Rollups and verify their correctness."

In other words, if native Rollup becomes a reality, then in the future, whether it is a transaction occurring on L1 or a transaction occurring on native Rollup, its final settlement and security will be guaranteed by the same group of Ethereum validators, and the trust level will be exactly the same.

This means that depositing $10 million on a native Rollup will be as secure as depositing it directly on the Ethereum mainnet.

Declan Fox, project leader of Linea, said that their long-term goal is to become a native Rollup. He believes that this is an "upgraded version" of the ETH 2.0 sharding solution - no longer rigidly running 64 shard chains with the same structure, but building a heterogeneous Rollup system in a highly programmable and customizable way to serve different scenarios and user needs.

Unlike the homogeneous sharding architecture of ETH 2.0 in the past, native Rollup can be heterogeneous, providing end users with a more diverse and differentiated application experience.

Although native Rollup has not yet been officially included in the Ethereum roadmap, with the official launch of zkEVM and the gradual reconstruction of the L1 architecture, pre-setting interfaces and pre-compiled logic for it has clearly become a foreseeable technological trend.

Ladislaus concluded, “Ethereum has a high degree of technical synergy between Snarkifying the EVM (i.e., integrating ZK proof capabilities) and promoting native Rollups, as the two share the underlying ZK technology stack.” Of course, this process still needs to go through Ethereum community governance, form an EIP (Ethereum Improvement Proposal), and ultimately be deployed in a hard fork.

If everything goes well and we are optimistic, the relevant EIP may be submitted by the end of the year and launched in the fork after the Glamsterdam upgrade.

However, this timetable remains highly uncertain and needs to be viewed with caution.