Vitalik Buterin, the co-founder of Ethereum (ETH), has ignited a debate about the classification of various layer 2 scaling solutions.
The crypto veteran has claimed that Ethereum’s validiums should not be considered genuine rollup solutions.
The statement came in response to a post by Daniel Wang, the founder of Taiko, an Ethereum rollup solution, who said if an Ethereum rollup relies on an external data chain, such as Celestia’s modular blockchain, then it should be classified as a validium.
Buterin concurred with Wang’s comment, stating:
“This is correct. The core of being a rollup is the unconditional security guarantee: you can get your assets out even if everyone else colludes against you.”
He emphasized that if data availability depends on an external system, that security guarantee cannot be upheld.
This is correct.
The core of being a rollup is the unconditional security guarantee: you can get your assets out even if everyone else colludes against you. Can’t get that if DA is dependent on an external system.
But being a validium is a correct choice for many apps, and…
— vitalik.eth (@VitalikButerin) January 16, 2024
What is Validium?
Validium is a scaling solution for Ethereum that utilizes zero-knowledge proofs to enable off-chain transactions, while still relying on the Ethereum mainnet for security and verification.
Unlike ZK-rollups, which batch transactions on a layer 2 network and verify them on a layer 1 like Ethereum, validium networks do not post transaction data to layer 1.
Instead, they post cryptographic proofs of transaction validity, aiming to achieve higher scalability by avoiding the need to store full transaction data on-chain.
However, compared to rollups, validiums face challenges in terms of data availability, as they rely on operators to honestly post proofs.
Networks like Celestia employ modular blockchains consisting of data availability layers and validation layers, with validiums facilitating fast and private transactions.
Buterin took to the decentralized social media platform Warpcast to share a diagram proposing adjustments to terminologies related to these scaling solutions.
He suggested replacing terms like “security-favoring” and “scale-favoring” with “strong” and “light” to achieve greater brevity.
Some Argue Validiums Should Be Considered L2 Networks
While Buterin’s proposals garnered support, not everyone agreed.
Ryan Berckmans, a member of the Ethereum community, argued that validiums should be considered layer 2 networks.
“A layer-2 is a chain that settles on Ethereum. I’ll die on this hill, and I’ll debate anyone who insists the [data availability] has to be on Ethereum for it to be an L2,” he said.
Berckmans believed that the definition of layer 2 should encompass both rollups and validiums.
However, a layer 2 industry analytics platform called L2Beat contradicted Berckmans’ perspective, asserting that validiums are not layer 2 solutions.
According to L2Beat, validiums and optimiums introduce additional trust assumptions by not publishing data on layer 1.
As reported, Ethereum-based layer 2 network Arbitrum now has a market share of 49.17% among layer 2 networks, far surpassing number two on the list, Optimism Mainnet, with its 28.85% market share.
The network has also seen a consistent increase in its TVL at least since October last year, rising about 50% from $1.66 billion in October to the current value of $2.51 billion, data from DeFi tracking site DefiLlama showed.
The upcoming Ethereum Dencun upgrade, incorporating changes proposed by EIP-4844, is expected to reduce rollup transaction costs, benefiting layer 2 solutions like Arbitrum by lowering gas fees and improving network capacity.