Polygon co-founder proposes zkEVM ‘validium’ upgrade to improve security

Polygon co-founder Mihailo Bjelic has proposed upgrading the Polygon Proof of Stake (PoS) network to a “zkEVM validium” version, according to a June 20 forum post. If the upgrade is implemented, the new version will rely on zero-knowledge proofs to increase security.

HUGE UPDATE ON #Polygon

Polygon may go through some huge changes in near future. @MihailoBjelic shared a polygon improvement proposal few hours ago which discussed to upgrade polygon POS to zkEVM Validium.

According to the proposal, Polygon POS is facing three key challenges…

— Hitesh Malviya (@hmalviya9) June 20, 2023

Polygon PoS is an Ethereum scaling solution that has over $900 million total value locked within its contracts and does over 2 million transactions per day. It was first launched in 2019. In March, the Polygon team launched a second network, Polygon zkEVM, that uses zero-knowledge proof rollups to scale Ethereum.

In the June 20 post, Bjelic proposed to also upgrade the old PoS network to a zkEVM version, making both networks rely on zero-knowledge proofs. However, unlike the network that just launched in March, the new version of Polygon PoS will not be a “rollup,” Bjelic stated. In other words, it will not store compressed transaction data on Ethereum. Instead, it will be a “validium” that stores only validation proofs on layer 1, while the actual transaction data will be kept on a separate chain.

This compromise will allow Polygon PoS to have lower transaction fees than Polygon zkEVM. It will also increase the security of Polygon PoS, since it will allow the network to inherit Ethereum’s security, the co-founder concluded.

Related: Why ZK-rollups need data availability

Once the upgrade is implemented, Polygon zkEVM may be used for high-value transactions where security is of the utmost importance, whereas Polygon PoS may become the network for gaming and social media enthusiasts, Bjelic suggested, stating:

“Upgraded Polygon PoS (zkEVM validium) would offer very high scalability and very low fees, with the tradeoff of storing transaction data locally instead of on Ethereum. It would be a great fit for applications that have high transaction volume and require low transaction fees, e.g. Web3 gaming and social.”

The Polygon co-founder offered a timeline for when he thought the upgrade could be implemented, stating that his informal proposal could be turned into a formal Polygon Improvement Proposal (PIP) by November and implemented on mainnet sometime between…