4 layer 2s that helped Ethereum scale in 2023

Ethereum's ongoing evolution gathered pace in 2023, with the ecosystem shifting focus to scalable solutions and protocols to improve throughput and reduce costs for decentralized applications (DApps) and users.

The transition from energy-based proof-of-stake mining to proof-of-stake agreements laid the groundwork for improvements that previously seemed impossible before the merger. Many approaches have been developed to allow the network to handle more transactions without increasing the size of the nodes.

Layer-2 solutions have become the preferred method for scaling the Ethereum ecosystem. Operating independently of the Ethereum chain, these networks process transactions as “packages” before submitting the summary data to Ethereum. Rollups aim to increase Ethereum production and reduce transaction costs for users.

Related: Are ZK-Proofs the Answer to Bitcoin's Ordinary and BRC-20 Problem?

Ethereum currently has two types of coils that support network scaling. The first promising move is to execute transactions off-chain and post the transaction data to the main network as call data.

As the Ethereum data base explains, these scrolls are labeled “bright” because they assume off-chain transactions are valid and do not publish validations for transactions posted on-chain.

This differs from zero-knowledge rollups (ZK-rollups), which include transactions off-chain but provide validation of the changes needed to represent all transactions as a group.

Proof of authenticity is generally a cryptographic proof that intended state changes are caused by the transactions themselves. ZK-rollups should only provide validation checks to complete transactions, rather than posting all transaction data on-chain as optimists.

Related: Ethereum Proto-Dunksharding to Make Bundles 10x Cheaper – Consensys zkEVM Linea head

There is no delay when transferring funds from ZK-rollup to the Ethereum mainnet because transactions are executed when the ZK-rollup contract verifies its validity. Opting out of Bright Packs has a delay that allows users to perform fraud proofs to double check the authenticity of packaged transactions.

Although opinions differ, ZK-powered Layer 2s are becoming more popular in 2023 as they bypass the need for tamper proofs. A few solutions supported by the technology have taken center stage, and Cointelegraph takes a look at the main players that have emerged this year.

Polygon zkEVM

Polygon has become a household name in the Ethereum scale ecosystem, and the protocol has made significant strides in developing the technology stack in 2023. Layer-2 protocols powered on Ethereum tailored to their project requirements.

Polygon has released its open source zkEVM mainnet beta in March 2023, which includes reduced transaction costs and a number of smart contract agreements. The technology allows thousands of transactions to be distributed off-chain, with cryptographic verification of a small summary of data posted on the Ethereum mainnet.

Polygon's zkEVM simulates the Ethereum mainnet transaction execution environment. Open source zkEVM enables DApps to scale at transaction volume, unlocking high performance.

Polygon's zkEVM browser reflects the usage of the network since its launch in March 2013 with over 8.6 million transactions to date. Over the past six months, the network has averaged 20,000 to 40,000 Ethereum transactions per day.

ZkSync era

ZkSync Era claims to be the first Ethereum virtual machine-compatible ZK-rollup to launch an alpha version of the network, which it did in February 2023 after a long four years since it was launched by Matter Labs.

An alpha report released the following month revealed that major decentralized finance players – including Uniswap, Sushi, Suri and Curve – launched on zkEVM.

The network has since attracted a significant user base, with data from DappRadar reflecting more than 150 active DApps at the time of writing. The network also has 6.2 million unique active wallets and has processed more than 200 million transactions at seven transactions per second, according to data from L2scan.

Line

Consensys, the development company behind major Ethereum products such as MetaMask, has joined the ZK-rollup competition with the zkEVM network, Linea.

The platform allows Ethereum developers to deploy or migrate DApps to the network and went live with its alpha release in July 2023. Linea is integrated with the Ethereum browser-based wallet MetaMask, allowing Linea users to find, exchange and purchase functionality of the token bridge.

Linea completed its official launch in August 2023 and raised more than $26 million in Ether (ETH) in its first month of bridge creation. Linea currently has over 2 million unique active wallets and has processed 34 million transactions since its launch to Mynet. Data from L2scan also reflects that the network can process five transactions per second.

Starknet

Starknet joins the list of Layer 2s that launched Ethereum, acting as a true rollup or ZK-rollup. It is not classified as zkEVM because it runs on the native Cairo virtual machine and programming language.

According to Starknet's developer resource, the Cairo VM is said to be purpose-built for authentication systems and optimized for memory access. Starknet explained that EVM requires more computation to generate memory proofs for reading and writing.

Although it runs on a different type of virtual machine, STARKnet wraps transactions into off-chain STARK authentication, providing the same functionality as Polygon zkEVM, Linea, and zkSync Era.

At the time of writing, Starknet ecosystem metrics reflect 48,104 ETH connected to the network, worth $108 million. Layer 2 performed 19.4 million transactions

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ZK-rollups continue to draw significant value from the broader Ethereum ecosystem, given the increased throughput and reduced costs provided by the central players touched on above.

The latter half of 2023 also saw the likes of Scroll, another zkEVM, go live, showing the increasing number of ZK-powered layer 2s coming online.

But there is plenty of room for healthy competition. Several project leaders have openly told Cointelegraph that various ZK-powered platforms will serve to make the Ethereum ecosystem stronger.

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