Data Availability Solutions Overview

Data availability ( DA ) is crucial for Layer 2, primarily involving a 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 a solution for Ethereum to reduce DA costs. It introduces the Blob transaction format, allowing L2 to perform non-permanent data storage on the Ethereum consensus layer at a lower cost. This makes Ethereum a real-time bulletin board, where data will be deleted after a certain period, and L2 must store data backups on their own. Proto-Danksharding is expected to go live in the Ethereum Cancun upgrade at the end of this year.

Off-chain Solutions

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

Validium

Validium is a highly centralized DA solution, with transaction data managed by centralized operators. While it maximally protects transaction privacy and reduces DA costs, it carries higher risks, as issues with the operators may result in users being unable to recover their funds.

Data Availability Committee ( DAC )

To reduce the risk of single points of failure, Validium is usually used in conjunction with DAC. DAC is similar to a consortium chain, consisting of multiple trusted nodes that keep copies of transaction data and disclose data when necessary. Although the cost is lower, small-scale DACs still have security risks.

Volition

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

General DA Solution

Some DA solutions serve not only Ethereum L2 but also provide data availability for more chains and projects. These solutions typically have their own validation nodes, block producers, and consensus mechanisms to enhance security, but do not support smart contracts.

Introduction to DA Layer Projects

StarkEx

StarkEx is a scalability solution framework developed by the StarkWare team, providing three DA modes: on-chain, Validium, and Volition. Its Validium solution integrates DAC to enhance security. Currently, multiple projects are using StarkEx for DA.

zkPorter

zkPorter is an off-chain DA solution proposed by Matter Labs, designed as a standalone chain specifically for L2 to publish transaction data. It maintains security through PoS consensus, and zkSync token holders can stake to become validators. However, this solution has not yet made any concrete progress.

EigenDA

EigenDA is a DA layer project developed based on EigenLayer. Unlike other general-purpose DA projects, EigenDA is a middleware that does not have its own consensus mechanism; its security comes from the restaking model of Ethereum validators on EigenLayer. Multiple L2 projects plan to integrate EigenDA.

Celestia

Celestia is a general-purpose DA public chain with its own validation nodes and PoS consensus mechanism. Although the costs are high, its security is significantly higher than other off-chain DA solutions. Celestia recently announced an airdrop plan, which has sparked interest in modular blockchains and DA layers.

Avail

Avail was originally a Polygon project and is now operating independently. As a DA public chain, it is technically more complex than Celestia. Avail is currently in the testnet phase, offering various participation methods, including obtaining test tokens and developing integrated applications.

Summary

Ethereum aims to lower the cost of publishing data for L2 through EIP-4844, while retaining the functions of the DA layer, settlement layer, and consensus layer. This creates direct competition for off-chain DA solutions with Ethereum. It is worth paying attention to how future DA layer projects can enhance their competitiveness, and whether large projects similar to Optimism and Arbitrum will emerge.