In-Depth Analysis of Ethereum Scalability Solutions

Ethereum, as an important platform in the blockchain field, hosts a large number of decentralized applications, from DeFi to NFTs, and the ecosystem is flourishing. However, with this comes issues such as network congestion, soaring transaction fees, and extended confirmation times, which seriously affect users' enthusiasm for participation.

To address these issues and maintain the decentralized characteristics of the main chain, the community primarily adopted the L2 scaling solution. The core idea of L2 is to shift computation and transactions from the main network (L1) to a second-layer network for execution, only submitting the final results to the main network. This approach not only improves transaction efficiency and reduces costs but also inherits the security of the main network.

Currently, the more popular L2 solutions include Rollups and sidechains. Rollups can be further divided into Optimistic Rollups (OP-Rollups) and Zero-Knowledge Rollups (ZK-Rollups).

Optimistic Rollups

OP-Rollups perform transaction computation and state updates on the L2 network, and then publish compressed raw data in batches to the mainnet. L2 nodes assume these transactions are valid by default, adopting the principle of "presumption of innocence." This model greatly enhances transaction confirmation speed and efficiency.

After the transaction is submitted, if the validator finds an issue, they can submit a fraud proof within seven days. The mainnet smart contract will verify this proof. If a problem indeed exists, the involved transaction batch and subsequent batches will be rolled back, the malicious node will be punished, and the validator will receive a reward.

The existence of the "fraud proof" mechanism itself has a strong deterrent effect, and in reality, very few nodes submit fraud proofs. This is attributed to the thorough testing of the project itself, a strict punishment mechanism, and the significant economic and reputational losses that come from wrongdoing.

The main disadvantage of OP-Rollups is that the seven-day challenge period may affect the flow of funds and poses a potential centralization risk.

Zero-Knowledge Rollups

Unlike OP-Rollups, ZK-Rollups need to attach validity proofs when submitting data. It also processes transactions off-chain, but before formally submitting, it needs to calculate validity proofs off-chain.

The advantage of ZK technology in blockchain applications lies in its ability to limit complexity within the scope of smart contracts. Users only need to trust decentralized smart contracts without relying on any centralized entity.

The complexity of ZK-Rollups lies in the need to compile the transaction execution process into complex logical circuit diagrams, and then generate quickly verifiable results through cryptographic calculations. This often requires specialized compilers and verifiers to accomplish.

Layer2 Cost Analysis

Although L2 networks are designed to reduce the interaction costs for users on L1, they also have their own costs.

The costs of OP-Rollups mainly include the transaction fees for submitting compressed data to L1 and the operating costs of L2 nodes. Ethereum's EIP-4844 upgrade has significantly reduced the costs of interaction between L2 and the mainnet. In addition, node maintenance requires locking a large amount of funds, which may cause investors to miss out on other opportunities.

The main cost of ZK-Rollups comes from computational resources, as generating zero-knowledge proofs requires a large amount of computational resources and specialized hardware. At the same time, it also incurs transaction fees for submitting data to the main chain. The demand for specialized hardware may lead to increased centralization of the network.

Summary

Both OP-Rollups and ZK-Rollups are important solutions for the Ethereum ecosystem to address scalability challenges. With the implementation of upgrades such as Ethereum EIP-4844, the data publishing costs for L2 have been significantly reduced, which will further unleash the potential of both solutions and drive the continuous development of the Ethereum ecosystem.