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. Currently, there are two types of DA solutions: on-chain and off-chain.

On-Chain Solutions: Proto-Danksharding

Proto-Danksharding (EIP-4844) is Ethereum's solution to reduce DA costs. It introduces a new Blob transaction format that temporarily stores L2 transaction data on Ethereum's consensus layer. This turns Ethereum into a real-time bulletin board, where data is publicly displayed for a short period and then deleted, with L2 needing to back up the data themselves. Proto-Danksharding is expected to go live with the Ethereum upgrade at the end of this year.

Off-chain Solutions

Off-chain solutions no longer use Ethereum as the DA layer, but seek more cost-effective DA methods. Based on decentralization and security, it can be divided into:

Validium

Validium publishes transaction data off-chain and is managed by centralized operators. While it has the lowest costs and strong privacy, it also carries the highest risks. If the operator encounters issues, user funds may be unrecoverable.

Data Availability Committee ( DAC )

DAC is similar to a consortium blockchain, composed of multiple trusted nodes that maintain copies of transaction data. Data can be made public in case of issues with the operators. The cost is relatively low, but small-scale DACs still have security risks.

Volition

Volition allows users to choose whether to put a single transaction's data on-chain. It can be switched back on-chain after frequent off-chain transactions, partially inheriting Ethereum's security.

Universal DA Solution

Not limited to the Ethereum ecosystem, it can provide DA services for multiple chains and projects, such as EigenDA, Celestia, Avail, etc. These types of solutions typically have their own validation nodes and consensus mechanisms to enhance security to the level of public chains.

Main DA Projects

StarkEx

The scaling framework developed by StarkWare provides three DA modes: on-chain, Validium, and Volition. It has already served projects like dYdX v3 and Immutable.

zkPorter

The independent DA chain proposed by the zkSync team maintains security through PoS consensus. It can seamlessly interact with zkSync Era, but the current progress is unclear.

EigenDA

DA middleware developed based on EigenLayer. Security is obtained through ETH re-staking, and multiple L2 projects have already integrated.

Celestia

General-purpose DA public chain with independent verification nodes and PoS consensus. Celestium is an Ethereum L2 that uses Celestia as the DA layer. Celestia has completed two rounds of financing and announced airdrops for developers and active users.

Avail

An independent DA public chain originating from Polygon. The technology is relatively complex, and the main net is expected to go live in Q1 2024. Currently in the second phase of the test net, it offers various participation methods.

Thinking

Ethereum plans to reduce DA costs for L2 through EIP-4844, hoping to retain DA, settlement, and consensus functions. This allows off-chain DA projects to potentially compete directly with Ethereum. It is worth paying attention to whether important projects like Optimism and Arbitrum can emerge in the future DA layer.