Vitalik Buterin: "L2 on Celestia Are Validiums, Not True Rollups"

Vitalik Buterin, one of the co-founders of Ethereum, recently engaged in a conversation about the classification of various Layer 2 scaling solutions. He concurred with Daniel Wang, the founder of Ethereum aggregation solution Taiko, who argued that if Ethereum's aggregation relies on another blockchain for data availability, such as Celestia's modular blockchain, then it should be considered a Validium of Ethereum.

Buterin agreed, stating, "That's correct. The essence of aggregation is unconditional security: you can get your assets even if everyone else conspires against you. This is impossible to achieve if data availability depends on an external system."

Validium is a scaling solution for Ethereum that utilizes zero-knowledge proofs to process transactions off-chain while relying on the Ethereum mainnet for security and verification. Unlike zero-knowledge rollups that group transactions on Layer 2 and verify them on Layer 1 (e.g., Ethereum), Validium-based networks do not send transaction data to Layer 1. Instead, they publish cryptographic proofs of transaction validity, aiming to achieve higher scalability by not storing full transaction data on the blockchain.

However, Validiums depend on operators to honestly publish proofs and may have lower data availability compared to aggregated data networks. Platforms like Celestia (TIA) use a modular blockchain consisting of a data availability layer and a verification layer, with the latter using Validium to facilitate fast and confidential transactions.

Not everyone agrees with Buterin's proposals, including Ethereum community member Ryan Berkmans, who insists that Validiums are still Layer 2 networks.

"Layer 2 is Ethereum-based blockchain," he argued. "I will die on this hill and argue with anyone who insists that data availability must be on Ethereum for it to be L2. This is a new industry; we can define anything as 'L2' as we wish. The most useful definition of L2 includes both rollups and Validiums."

Despite Berkmans' statements, the Layer 2 analytics platform L2Beat maintains that Validiums are not considered Layer 2 networks. This ongoing debate highlights the evolving nature of the Ethereum ecosystem and the need for clear terminology in the world of blockchain scalability solutions.