Ethereum Polygon’s Layer 2 scaling protocol (MATIC) performs performance testing of zero-knowledge rollup technology (zk rollups) before full integration with its mainnet.
Development of the technology, called Polygon zkEVM (Ethereum Virtual Machine), has been underway for more than three years by the Polygon Hermez team. The team has already confirmed that zero-knowledge proofs are possible on Ethereum, generating over 12,000 zk proofs in a major testnet release zkEVM.
David Schwartz, project manager of Polygon zkEVM and PolygonID, revealed the development of the feature in correspondence with Cointelegraph. Layer 2 platforms have continued to evolve and improve functionality, which has played a key role in Ethereum’s scalability.
As he explained, zero-knowledge rollups have increased the speed at which Layer 2 platforms can achieve finality while ensuring secure transaction validation with zero-knowledge technology. In blockchain terms, finality is the point at which a block of transactions is considered to have been permanently and irreversibly added to the blockchain:
“Finally, we have zkEVMs, such as Polygon zkEVM, which offer all of the above in addition to equivalence with the Ethereum virtual machine with its advanced methods of zk-STARK and zk-SNARK.”
According to Schwartz, Polygon zkEVM includes the first available complete source code equivalent to EVM zkProver, which passes all Ethereum vector tests over 99%. He described completing proofs of validity for conventional user transactions as “the most challenging and rewarding endeavor” since his team began developing its native zkEVM.
Two years ago, the Polygon team estimated that developing zk rollups with EVM compatibility would take up to ten years. Given the progress made, the team describes zkEVM as the end game, combining advancements with Layer 2 scalability and rapid finality. This provides a myriad of benefits to users as they increase throughput and reduce fees.
Cointelegraph also questioned the difference between Polygon zkEVM and the proprietary ZK-SNARK and ZK-STARK technologies of Ethereum’s layer 2 scaling network, StarkNet. As discussed earlier, ZK-STARKS (Zero-Knowledge Scalable Transparent Argument of Knowledge) primarily increases scalability by bundling thousands of transactions with a single proof to confirm on-chain validity.
Related: What the Ethereum Merger Means for Layer 2 Blockchain Solutions
Schwartz said the main difference between the projects is that zkEVM focuses on native scaling of the Ethereum ecosystem instead of other zk-rollups just scaling transactions and improving performance in a different virtual machine form factor.
Polygon’s approach claims to meet the classification of a Type 2 zkEVM describe by Ethereum co-founder Vitalik Buterin in August 2022. According to Buterin’s summary, Type 2 zkEVMs aim to be fully compatible with existing applications, but make minor changes to Ethereum for easier development and generation faster evidence. Schwartz added:
“In contrast, StarkNet positions itself as a type 4, introducing a new high-level language and forcing transpilers to translate solidity code into their language.”
At the same time, Schwartz welcomed the opportunity to have more references and source code available from other projects in order to learn from different approaches. Activity on Ethereum layer 2 solutions continues to grow, with blockchain data showing that Arbitrum and Optimism transaction volume eclipsed transactions on the Ethereum mainnet through 2023.