Overview of Data Availability Solutions

When discussing blockchain scalability, one significant challenge faced by Layer2(L2) is the issue of data availability(DA). This involves a trade-off between security and cost. Currently, there are mainly two types of DA solutions: on-chain and off-chain.

On-chain Solution: Proto-Danksharding

Proto-Danksharding(EIP-4844) is a solution for Ethereum to reduce DA costs. It introduces the Blob transaction format, allowing L2 to temporarily store data on Ethereum at a lower cost. This turns Ethereum into a real-time bulletin board, where data will be deleted after a period of time. L2 needs to store data backups on its own. Proto-Danksharding is expected to go live in the Ethereum upgrade at the end of this year.

Off-chain Solutions

Off-chain solutions no longer rely on Ethereum as the DA layer, but seek more economical ways. Depending on the degree of decentralization and security, they can be divided into:

Validium

Validium is a highly centralized DA solution. Transaction data is managed by a centralized operator. Although it has the lowest cost, it also carries the highest risk. If the operator encounters issues, user funds may not be recoverable.

Data Availability Committee ( DAC )

DAC is similar to a consortium chain, consisting of multiple trusted nodes. They keep copies of the transaction data, which can be made public in case of operator issues. Although the costs are lower, small-scale DACs still pose security risks.

Volition

Volition is a hybrid model that allows users to choose whether to publish single transaction data on-chain or off-chain. This can partially inherit the security of Ethereum.

Universal DA Plan

Some projects like EigenDA, Celestia, and Avail provide general DA solutions that not only serve Ethereum L2 but also support other chains and projects. They typically have their own validation nodes, block producers, and consensus mechanisms, but do not support smart contracts.

DA Layer Project Introduction

StarkEx

StarkEx is a scalability framework developed by StarkWare, providing DA solutions for specific applications. It supports three modes: on-chain, Validium, and Volition. Current projects using StarkEx include dYdX v3 and Immutable.

zkPorter

zkPorter is an off-chain DA solution proposed by the zkSync team. It is an independent chain that maintains security through PoS consensus. zkSync token holders can stake to become validators. However, there is currently no clear development progress for zkPorter.

EigenDA

EigenDA, developed based on EigenLayer, is a middleware rather than an independent public chain. It obtains security through the re-staking model of EigenLayer. Many L2 projects integrate EigenDA, such as Mantle, Layer N, and others.

Celestia

Celestia is a general-purpose DA public chain with its own PoS consensus. It has launched the Celestium Ethereum L2, using Celestia as the DA layer. Celestia has completed two rounds of financing and announced an airdrop plan.

Avail

Avail was originally a Polygon project but is now operating independently. It is more complex than Celestia technology, with the mainnet expected to launch in Q1 2024. It is currently in the testnet phase, and users can participate in various ways.

Summary

Ethereum hopes to continue retaining DA functionality through EIP-4844. This could allow off-chain DA projects to potentially compete directly with Ethereum in the future. In addition to focusing on low costs, they also need to find new competitive advantages. For users, it is worth paying attention to whether large projects similar to Optimism and Arbitrum will emerge in the DA layer.