Vitalik Buterin Challenges L2 Classification: Celestia as Validiums, Not Authentic Rollups, Sparks Debate

Ethereum co-founder Vitalik Buterin recently engaged in a Twitter discussion, stating that layer 2 scaling solutions utilizing Celestia, such as Ethereum's validiums, should not be considered genuine rollups. This classification debate raises questions about the security and functionality of these solutions.

Vitalik Buterin's Clarification:

Rollups and Unconditional Security In response to a tweet by Daniel Wang, founder of Ethereum rollup solution Taiko, Buterin concurred that if an Ethereum rollup relies on an external data chain, like Celestia, it should be labeled as an Ethereum validium. He emphasized that the core characteristic of a rollup is the unconditional security guarantee, allowing users to retrieve their assets even if collusion occurs.

Validiums vs. ZK-Rollups:

Scaling Solutions Overview Validiums, like Celestia, utilize zero-knowledge proofs for off-chain transactions but depend on Ethereum's mainnet for security. Unlike ZK-rollups, which batch and verify transactions on Ethereum's layer 1, validium networks post cryptographic proofs instead of full transaction data, aiming for higher scalability. However, they rely on operators for proof honesty, potentially leading to reduced data availability compared to rollups.

Terminology Adjustment Proposal:

Buterin's Terminology Proposal Buterin proposed refining terminology like "security-favoring" and "scale-favoring" to "strong" vs "light" in a Warpcast post on Jan. 16. This adjustment aims for greater conciseness in describing various blockchain attributes.

Buterin’s proposed Ethereum scaling classifications. Source: Warpcast

Community Debate:

Differing Opinions While Buterin's classification found support, not everyone agreed. Ethereum community member Ryan Berckmans argued that validiums should be considered layer 2 networks, asserting that a layer 2 settles on Ethereum, irrespective of data availability. The debate raises questions about the industry's evolving definitions and interpretations.

L2Beat's Perspective:

Validiums as Not L2s In contrast to Berckmans' viewpoint, layer 2 industry analytics platform L2Beat contends that validiums, including Celestia, should not be classified as layer 2 solutions. Their argument is based on the additional trust assumptions introduced by validiums and optimiums when they refrain from publishing data on layer 1.

The ongoing debate highlights the evolving nature of blockchain terminology and the importance of clear classifications in understanding the functionalities and security guarantees of different scaling solutions. As the industry progresses, stakeholders must find consensus on definitions to ensure effective communication and understanding.