Overview of Data Availability Solutions

Data availability (DA) issues are a significant challenge faced by Layer 2, primarily involving the trade-off between security and cost. To address this issue, two types of solutions have emerged: on-chain and off-chain solutions.

On-chain Solutions: Proto-Danksharding

On-chain solutions refer to L2 continuing to use Ethereum as the DA layer and reducing data availability costs through Ethereum's own optimizations. Proto-Danksharding (EIP-4844) is the main solution for Ethereum to reduce DA costs, introducing a new Blob transaction format. The transaction data uploaded by L2 will be stored in a non-permanent manner as Blob on Ethereum's consensus layer, providing L2 with more economical data availability. This means Ethereum will become a real-time bulletin board, with data being deleted after a certain period, and L2 will need to store a complete data backup 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 refer to seeking other more economical ways to obtain data availability instead of using Ethereum as the DA layer. Off-chain solutions can be divided into four categories based on different levels of decentralization and security:

1. Validium: Data is managed by centralized operators, offering high privacy protection and very low DA costs, but with higher risks.

2. Data Availability Committee (DAC): Composed of multiple trusted nodes, similar to a consortium chain, used to reduce the risk of single points of failure.

3. Volition: A hybrid model that allows users to choose whether the data of a single transaction is published on-chain or off-chain.

4. General-purpose DA solutions: Not limited to the Ethereum ecosystem, they can provide services for multiple chains and projects. These solutions typically have independent validation nodes, block producers, and consensus mechanisms, but do not support smart contracts.

Introduction to DA Layer Projects

In modular blockchain architecture, the DA layer is still in its infancy. Here are a few DA layer projects worth paying attention to:

1. StarkEx: Developed by StarkWare, it provides scaling solutions for specific applications, supporting three DA modes: on-chain, Validium, and Volition.

2. zkPorter: An off-chain data availability solution proposed by the zkSync team at Matter Labs, it is an independent chain that maintains security through a PoS consensus mechanism.

3. EigenDA: A DA layer project developed based on EigenLayer, obtaining security through the restaking model of Ethereum validators.

4. Celestia: A general-purpose DA public chain with independent validating nodes and a PoS consensus mechanism, providing higher security than other off-chain solutions.

5. Avail: Originally a Polygon project, it is now an independently operated DA public chain with relatively complex technology. The mainnet is expected to go live in the first quarter of 2024.

Future Outlook

As Ethereum continues to advance optimization proposals like EIP-4844, off-chain DA solutions may face direct competition with Ethereum. In addition to focusing on lower costs, how to enhance competitiveness will be a key issue for these projects in the future. For users, whether there will be large-scale projects similar to Optimism and Arbitrum in the DA layer is worth looking forward to. At the same time, some projects like Celestia have begun to attract developers and users through token incentives, demonstrating a strategic intention to seize market share.