Layer 2 scaling is one of the most critical issues in the blockchain industry, and we need to develop robust solutions before the next crypto bull run! Early 2022 saw a lot of issues with the Ethereum L1 getting clogged with thousands and thousands of transactions, causing a lot of frustration for the NFT buyers and Defi traders. One of the most innovative and sought-after solutions is zkEVMs!

What is a zkEVM?

A zkEVM (Zero-Knowledge Ethereum Virtual Machine) is a variant of the Ethereum Virtual Machine (EVM) that allows for the creation and execution of smart contracts in a zero-knowledge setting.

A zkEVM allows for the execution of smart contracts in a way that preserves the privacy of the contract terms and the data involved in the contract. This is achieved through zero-knowledge proofs, which are cryptographic proofs that allow one party to prove to another party that a statement is true without revealing any additional information about the statement.

There are various zkEVMs, and it is essential to distinguish among them. While each of these types strives to build the best zkEVM, they all try to achieve this goal differently.

You can find a more in-depth technical explanation and the advantages and disadvantages of each type of zkEVMs in Vitalik’s blog here.

What is a zk-rollup?

A zk-rollup is a type of Layer 2 scaling solution for blockchain networks. It allows transactions to be processed off-chain and then “rolled up” into a single on-chain transaction, reducing the load on the main blockchain and increasing the transaction throughput.

In a zk-rollup, transactions are processed by a set of validators responsible for ensuring the correctness of the transactions. These validators create a zero-knowledge proof, which is a cryptographic proof that a statement is true without revealing any additional information about the statement. The zero-knowledge proof is then added to the on-chain transaction, allowing the transaction to be verified without needing each transaction to be processed on the main blockchain.

zkEVMs vs zk-rollups

One key difference between zk-rollups and zkEVMs is that a zk-rollup is focused on scalability, while zkEVM is focused on privacy. A zk-rollup allows for a large number of transactions to be processed off-chain while still maintaining the security and integrity of the Ethereum main chain. On the other hand, zkEVM allows for the execution of smart contracts in a privacy-preserving manner, allowing for the creation of private, confidential transactions on the Ethereum platform.

Both zk-rollup and zkEVM are significant innovations that can help to improve the scalability and privacy of Ethereum. They both have the potential to significantly enhance the capabilities of the Ethereum platform and make it more useful for a wide range of applications.

Having understood the basics of zkEVMs and zk-rollups, let’s take a closer look at the different projects implementing zkEVMs.

zkSync

zkSync is a layer-2 scaling solution for Ethereum, which aims to increase the scalability and speed of the Ethereum network. It is based on zero-knowledge proofs, which allow transactions to be verified without revealing the underlying data. This allows zkSync to process transactions off-chain, which means that they are not recorded on the Ethereum blockchain itself. Instead, they are recorded on a separate, off-chain data structure called a “Merkle tree.”

One of the key features of zkSync is its use of “optimistic” transfers, which allow users to send and receive transactions without waiting for them to be confirmed on the Ethereum blockchain. This significantly reduces transaction times and allows for much higher transaction throughput.

In addition to using zero-knowledge proofs and optimistic transfers, zkSync also utilizes several other technologies to increase scalability and security. These include signature aggregation, which allows for the compression of multiple signatures into a single signature, and multi-chain support, which helps zkSync to interact with other blockchain networks.

Overall, zkSync aims to provide a scalable and secure platform for decentralized applications (dApps) and other Ethereum-based projects. By allowing for faster and more efficient transactions, it aims to make it easier for developers to build and deploy dApps, and for users to interact with them.

One of the main challenges faced by zkSync is the need to balance scalability with security. While using zero-knowledge proofs and other technologies allows for faster and more efficient transactions, it also introduces additional complexity and potential vulnerabilities. As such, zkSync is constantly working to improve and refine its technology to ensure it is as secure and robust as possible.

Despite these challenges, zkSync has made significant progress since its launch in 2020 and has already gained a strong following among developers and users. Its unique approach to scaling Ethereum has attracted considerable attention and investment, and it has the potential to play a significant role in the future development of the Ethereum ecosystem.

Starkware StarkNet

Starkware is a project that has developed a protocol called StarkNet. StarkNet is a layer-2 scaling solution that aims to increase the efficiency and scalability of blockchains, particularly those that use smart contracts.

One key feature of StarkNet is its use of STARKs, which are zero-knowledge proof systems that allow users to prove the correctness of a computation without revealing the underlying data. This allows for greater privacy and security on the network and the ability to perform complex computations without the need for a trusted third party.

StarkNet also utilizes sharding, a technique that allows a blockchain to be split into multiple smaller chains, or “shards,” that can be processed in parallel. This allows for greater throughput and faster transaction times, as each shard can be processed independently of the others.

One of the main goals of StarkNet is to enable the creation of decentralized finance (DeFi) applications on a mass scale. DeFi apps often rely on smart contracts and other complex computations, which can strain the underlying blockchain and limit its scalability. By using StarkNet, DeFi developers can create more efficient and scalable applications that can handle a larger volume of transactions.

StarkNet has already been integrated with several popular blockchains, including Ethereum, Binance Smart Chain, and Polkadot. This allows developers to build DeFi applications on top of these platforms using StarkNet without worrying about scalability issues.

In addition to its focus on DeFi, StarkNet is also being used in various other applications, including supply chain management, voting systems, and even medical research. The versatility and scalability of the protocol make it an attractive choice for a wide range of use cases.

Overall, Starkware’s StarkNet protocol represents a significant advancement in blockchain technology. Its use of STARKs and sharding allows for greater efficiency, privacy, and scalability, making it an ideal solution for various applications, particularly those in the DeFi space.

Polygon Hermez

The Polygon blockchain project has recently introduced a new technology called the Hermez zkEVM. This technology is designed to improve the scalability and privacy of the Ethereum blockchain.

The Hermez zkEVM aims to address the scalability issue of the Ethereum blockchain by using zero-knowledge proofs to allow for faster and cheaper transactions on the Ethereum network. In the context of the Hermez zkEVM, zero-knowledge proofs can be used to verify the correctness of transactions without disclosing specific details. This allows for faster transaction processing and reduced fees, as there is no need for the entire network to validate each transaction.

In addition to improving scalability, the Hermez zkEVM also enhances the privacy of the Ethereum network. By using zero-knowledge proofs, the Hermez zkEVM allows for confidential transactions that hide the specific details of a transaction from all parties except the sender and the recipient. This can be useful for various applications, such as allowing individuals to make financial transactions without revealing their identity or allowing companies to conduct business without disclosing sensitive financial information. As mentioned earlier in the various types of zkEVMs, this implementation by Polygon is compatible at the bytecode-level rather than at the language level.

The Hermez zkEVM is a promising development for the Ethereum network and the broader blockchain community. By improving scalability and privacy, it has the potential to make the Ethereum network more attractive for a wide range of dApps and use cases. It will be interesting to see how this technology is adopted and how it may impact the future development of the Ethereum network and other blockchain platforms.

Scroll

Scroll is a decentralized protocol that aims to bring scalability and increased security to the Ethereum blockchain. One of the key features of Scroll is its use of zk-rollups, a type of layer 2 scaling solution that allows for faster and cheaper transactions while maintaining the security of the main blockchain.

In a zk-rollup, transactions are bundled together and verified by a smart contract on the main blockchain. This allows for a much higher transaction throughput, as the burden of verifying each individual transaction is removed from the main chain and placed onto the rollup contract.

Scroll specifically focuses on creating an EVM-compatible zk-rollup, which means it can support the same programming languages and smart contracts as Ethereum. This is important because it allows developers to easily migrate their existing applications to the Scroll network without making any changes to their code.

Overall, Scroll is a promising project working to bring the benefits of zk-rollups to the Ethereum ecosystem. By creating an EVM-compatible solution, Scroll can offer developers a simple way to scale their applications and take advantage of the increased security and efficiency of zk-rollups. As the Ethereum network continues to grow and the demand for scalable solutions increases, projects like Scroll will play a crucial role in the evolution of the blockchain industry.

Consensys and Infura

ConsenSys and Infura, two of the most prominent names in the Ethereum ecosystem, are working on a new version of the Ethereum Virtual Machine (EVM) called zkEVM. This project aims to improve the scalability of Ethereum, which has been a significant challenge for the platform.

ConsenSys and Infura are working on integrating zkEVM into the Ethereum mainnet, allowing it to be used by anyone on the network. This is an exciting development for the Ethereum community, as it has the potential to address some of the scalability challenges that have held the platform back in the past.

While the company hasn’t released many details about this project, their implementation approach and other things, this remains one of the most exciting projects for developers to follow. Consensys has built some of the core infrastructure that underpins the Ethereum ecosystem, and there would be no surprise if this zkEVM implementation becomes one of the most popular among the crowd.

Taiko

Taiko brands itself as a “Type 1 zkEVM — Fully decentralized, Ethereum-equivalent zk-rollup” on its website. They claim that being a Type 1 zkEVM is one of the major differentiators compared to the other projects on this list. They make almost no changes to the Ethereum architecture, which includes the hash function, state trees or gas costs. By doing this, they can reuse the execution client implementations with as few modifications as possible. One of the main advantages of using a Type 1 zkEVM like Taiko is the ease of migration without many changes to your code. For example, you can deploy on the Ethereum L1 and then migrate to Taiko. On the other hand, you could also first deploy on Taiko and then migrate to any other EVM-compatible chain afterwards.

Daniel Wang is the founder of Taiko, who was previously the founder of Loopring until he stepped down from that position in 2021. This happened just before the Loopring deal with Gamestop. While there was some speculation in the community as to why this happened, there has never been any bad blood between the two.

https://medium.datadriveninvestor.com/6-zkevm-projects-the-key-to-ethereums-scalable-future-12af0bab4f1d