Overview of Data Availability Solutions

When discussing the data availability (DA) issues faced by Layer 2, it mainly involves a trade-off between security and cost. To address this challenge, the industry has proposed two types of DA solutions: on-chain and off-chain.

On-chain Solutions: Proto-Danksharding

Proto-Danksharding(, also known as EIP-4844), is a solution for Ethereum to reduce the cost of data availability. It introduces a new transaction format called Blob, allowing L2 to store transaction data on the Ethereum consensus layer temporarily at a lower cost. This means that Ethereum will become a temporary bulletin board, and L2 will need to store data backups independently. Proto-Danksharding is expected to go live in the Ethereum Cancun upgrade at the end of this year.

Off-chain Solutions

Off-chain solutions no longer use Ethereum as the DA layer, but rather seek more economical data availability methods. Based on the differences in decentralization and security, they can be divided into four types:

1. Validium: Transaction data is managed by centralized operators, offering the lowest cost but the highest risk.

2. Data Availability Committee ( DAC ): Composed of multiple trusted nodes to reduce single point of failure risk, but small DACs still have security vulnerabilities.

3. Volition: Hybrid mode, allowing users to choose whether to put individual transaction data on the chain, balancing flexibility and some Ethereum security.

4. General DA Solutions: Not only serving Ethereum L2, but also providing data availability for other chains and projects. These solutions typically have independent validation nodes, block producers, and consensus mechanisms, aiming to achieve security close to that of public chains.

Main DA Layer Projects

StarkEx

StarkEx is a framework that provides scaling solutions for specific applications, supporting three DA modes: on-chain, Validium, and Volition. Its Validium solution combines DAC to enhance security. Currently, several well-known projects use StarkEx for data availability.

zkPorter

zkPorter is an off-chain DA solution proposed by the zkSync team, designed as an independent chain that maintains security through the PoS consensus mechanism. It allows for seamless interaction with zkSync Era, but currently, there is limited information on the development progress.

EigenDA

EigenDA is developed based on EigenLayer and operates as middleware rather than an independent public chain. It achieves security through the re-staking model of Ethereum validators on EigenLayer, making it the first active verification service on EigenLayer. Multiple L2 projects plan to integrate EigenDA.

Celestia

Celestia is a general-purpose DA public chain, featuring independent validation nodes and a PoS consensus mechanism. Although the costs are higher, its security significantly surpasses that of other off-chain solutions. Celestia has completed multiple rounds of financing and plans to conduct a token airdrop, attracting industry attention.

Avail

Avail was originally a Polygon project and is now an independently operating DA public chain. Its technology is more complex than Celestia, with the mainnet expected to launch in the first quarter of 2024. It is currently in the testnet phase, providing various participation options for developers and users.

Future Outlook

As Ethereum plans to further reduce L2 data publishing costs through EIP-4844, off-chain DA solutions may face direct competition with Ethereum. It is worth keeping an eye on how these projects can enhance their competitiveness in the future and whether large-scale applications similar to Optimism and Arbitrum can emerge.