Latest Advances in ZK Technology

Zero-knowledge proof (ZK) technology is no longer a novelty in the crypto world. However, due to its diverse implementation methods, tracking the specific progress can be challenging. This article will outline the latest developments in ZK technology.

The Modular Trend of Ethereum

Ethereum is transitioning from an early monolithic architecture to a more modular design. An increasing number of third-party solutions are being used to enhance Ethereum’s data and execution capabilities.

In terms of data availability, there are projects like Celestia and Polygon Avail. On the execution layer, second layer (L2) solutions such as Arbitrum and zkSync have emerged, which execute transactions off-chain and then batch them to the Ethereum main chain, providing a faster and lower-cost user experience.

The current transaction processing capacity of the Ethereum mainnet is about 30 transactions per second ( TPS ). To meet the global demand for activity, Ethereum is increasingly relying on scaling innovations to optimize its execution capabilities. There are mainly two types of solutions: on-chain scaling and off-chain scaling.

On-chain scaling refers to directly modifying the blockchain to increase transaction processing capacity. For Ethereum, sharding is an example, which will distribute the active load across multiple parallel Ethereum chains.

Off-chain scaling refers to the establishment of an execution environment outside of Ethereum, namely L2, which facilitates cheap and fast transactions, and then batches the transaction data for publication to the Ethereum main chain. This method fosters a secondary network composed of multiple customizable rollups.

ZK rollups: Leading ZK-based off-chain scaling technology

The most popular L2 solution currently is zero-knowledge rollup ( ZK rollup ). These rollups can increase transaction processing speeds to about 2000 TPS, which is 65 times the current speed of the Ethereum mainnet.

ZK rollups use zero-knowledge proofs ( ZKP ) technology ( like SNARKs ) to encrypt verification and publish their transaction batches on Ethereum. Currently, larger scale ZK rollups include:

• dYdX: Cryptocurrency and derivatives exchange
• Loopring: L2 for trading and NFTs
• zkSync Lite: L2 for trading and NFTs
• ZKSpace: L2 for transactions and NFTs
• Aztec Connect: L2 for privacy DeFi

The current mainstream ZK rollups either use StarkEx technology (, such as dYdX and Loopring ), or are based on zkSync code (, such as zkSync Lite and ZKSpace ). In addition, there are some independent ZK rollups worth noting, such as Aztec Connect.

Validium and Volition

In addition to ZK rollup, ZK-based scaling solutions also include Validium and Volition.

Validium executes transactions off-chain and maintains data through off-chain zero-knowledge proofs. Unlike ZK rollups that batch data sent on-chain, Validium’s data is fully stored off-chain. This makes Validium a custodial solution, but with superior performance, achieving over 20,000 transactions per second.

Currently known Validium projects include:

• Immutable X: NFT-centric scaling solution
• Sorare: Fantasy Sports Digital Card Game
• ApeX, rhino.fi, and Myria, etc.

Volition is an innovation developed by the StarkWare team, combining the features of ZK rollup and Validium. Users can freely choose between on-chain and off-chain data availability. zkSync’s zkPorter mechanism is a Volition system worth noting.

zkEVM: The Holy Grail of Scalability

zkEVM is a ZK rollup compatible with the Ethereum Virtual Machine (EVM). Its emergence represents an important step in Vitalik Buterin’s 2021 prediction - that ZK rollups will ultimately prevail in all use cases.

Due to the use of cryptographic proofs, ZK rollups have advantages in privacy and security over optimistic rollups. If EVM compatibility is added, ZK rollups are likely to surpass optimistic rollups in the future.

Currently, multiple teams are developing different types of zkEVM:

• Polygon zkEVM: Currently Type 3, progressing towards Type 2.
• Scroll: Building Type 2 zkEVM
• zkSync Era: a specially customized Type 4 zkEVM
• Starknet’s Kakarot zkEVM: has reached Type 3 level and is accelerating development

Latest Developments in zkEVM

• The Polygon zkEVM mainnet test version will start on March 27.
• zkSync Era has opened the mainnet to developers, and the version for regular users will be launched soon.
• Scroll has just released the Goerli zkEVM testnet, which is the final step before the mainnet launch.
• Starknet’s Kakarot zkEVM is already in Type 3 status and is accelerating its development.

In the future, Ethereum itself may upgrade to Type 1 zkEVM for further expansion. Meanwhile, external zkEVMs from Type 2 to Type 4 will continue to thrive, providing developers and users with unique customization features and enhanced user experiences.

2023 will be the year ordinary crypto users experience zkEVM for the first time. If you want to get involved, please keep a close eye on the latest developments from teams like Polygon, zkSync, Starknet, and Scroll.