What is zkSync? Ethereum's Scaling Solution

Last Updated:
May 19, 2023
What is zkSync - Feature Image

zkSync stands out as a promising Ethereum Layer 2 scaling solution, providing increased transaction speed, lower fees, and robust security. In this article, we will explore what zkSync is, how it works, and its role in the future of Ethereum and blockchain technology.

As the demand for blockchain technology continues to rise, the limitations of existing platforms have become increasingly apparent. One such platform, Ethereum, is facing major scalability issues. In response to these challenges, several solutions have emerged. Among them, zkSync stands out as a promising Ethereum Layer 2 scaling solution, providing increased transaction speed, lower fees, and robust security. In this article, we will explore what zkSync is, how it works, and its role in the future of Ethereum and blockchain technology.

Understanding zkSync

zkSync is a Layer 2 scaling solution for Ethereum, utilizing zero-knowledge rollups (zk-rollups) as the foundational technology. This technology offers a way to perform transactions off the Ethereum mainnet, with the proofs of these transactions later submitted to Ethereum. Simply put, hundreds of transactions are bundled into one, which is then verified and secured by the Ethereum network.

One of the key features of zkSync is the use of zero-knowledge-proof systems, which provide proactive cryptographic security. In essence, zk-rollups confirm the validity of a transaction without revealing its proof. This "trust me on this" approach might sound abstract, but zero-knowledge proofs are considered one of the most promising solutions for improving scalability and privacy in Ethereum.

zkSync's architecture significantly reduces gas fees on the Layer 2 blockchain. These fees can be up to 100 times lower than those on Ethereum, while still inheriting the security features of the Ethereum mainnet. This reduction in transaction costs makes zkSync a highly attractive solution for users and developers alike.

The future roadmap for zkSync also looks promising. An upcoming update, zkSync 2.0, aims to increase throughput to over 100,000 transactions per second once Ethereum 2.0's data sharding is available. This leap in performance is made possible by zkPorter, a protocol combining zk-rollups and sharding. Additionally, zkSync 2.0 plans to support arbitrary smart contract capabilities via Solidity and Zinc, its internal programming language.

zkSync in Comparison to Other Solutions

While zkSync is a remarkable solution, it's not the only player in the Ethereum Layer 2 field. Its main competitors are Layer 2 solutions using optimistic rollups, such as Arbitrum and Optimism, and other solutions using zk-proof scaling technology, like Starkware. There are key differences between these technologies.

Compared to optimistic rollups, zkSync's on-chain processing speed is higher as there's no waiting period during which the transaction can be disputed. However, zk-proof solutions like zkSync require more computational power, making them less suitable for decentralized applications (DApps) with high on-chain activity. Optimistic rollups can run smart contracts directly on the Ethereum network, while zk-rollups do not.

In the comparison between zkSync and Starkware, both zk-proof solutions, Starkware has an advantage in terms of its head start in development and larger ecosystem. Despite this, both technologies present viable approaches to scaling Ethereum, with zkSync being considered the more "grassroots" ecosystem.

The Development and Backing of zkSync

zkSync is a creation of Matter Labs, a Germany-based company dedicated to scaling Ethereum. The development of zkSync began in December 2019, with the first version released in June 2020, capable of scaling to 300 transactions per second. This throughput has been consistently improving, with a planned increase to 20,000 transactions per second thanks to zkPorter, a sharding solution.

Matter Labs has garnered substantial backing, raising $2 million in a seed round in September 2019, followed by $6 million in a Series A round in February 2021. Contributors to this round included prominent crypto companies like Binance, Aave, Curve, and Coinbase Ventures. Further funding rounds in November 2021 and January 2022 raised an additional $50 million and $200 million respectively, with venture capital funds like a16z, Dragonfly, Placeholder, and BitDAO being significant contributors.

The Technical Underpinnings of zkSync

Diving deeper into the technical aspects, zkSync utilizes zk-rollups, a technology that "rolls up" or bundles multiple transactions into a single proof. This proof, though containing many transactions, is compact and can be processed quickly on-chain, providing a solution to Ethereum's scalability issues.

zkSync's architecture consists of a smart contract on Ethereum and a set of servers called "operators." These operators collect a group of transactions, generate a zk-proof for these transactions, and submit the proof to the smart contract. In doing so, they take on the computational load that would have been handled by the Ethereum network, significantly reducing congestion and increasing transaction speed.

An important aspect of zkSync is its "zero-knowledge" feature, which means that even though transactions are validated and processed off-chain, the security and decentralization of Ethereum are not compromised. Each zk-proof submitted to Ethereum not only confirms the validity of all transactions but also ensures the current state of all accounts. This means that even if all operators become malicious or unresponsive, users can still withdraw their funds directly from the smart contract on Ethereum.


The growing demand for blockchain technology has made it essential for platforms like Ethereum to overcome scalability issues. zkSync, with its innovative use of zk-rollups, offers a scalable, secure, and efficient solution, making it a leading contender in the Layer 2 space.

As Ethereum continues to evolve with the upcoming release of Ethereum 2.0 and the widespread adoption of smart contracts, zkSync's role may become even more significant. Its ability to provide high throughput, low fees, and robust security makes it an invaluable tool for the Ethereum ecosystem and the future of blockchain technology.

As with all emerging technologies, the landscape is continually changing and evolving. However, with the robust development roadmap, strong backing, and proven technology, zkSync is well-positioned to play a crucial role in the future of Ethereum and the broader blockchain ecosystem.

In summary, zkSync is not just a solution to Ethereum's scalability problem; it's an integral part of the future of blockchain technology. Whether you're a blockchain developer, a cryptocurrency enthusiast, or an investor, keeping a close eye on zkSync's evolution is highly recommended.

Remember, the future of blockchain technology is being written today, and zkSync is one of the pens.