What are the differences in storage locations for Layer2 transaction records? Introduction to the development of off-chain data availability DA.

Where should the transaction information generated by Layer2 be stored? The solutions are diverse. Jianshu has compiled a summary of the mainstream data availability (DA) technology architectures from the past to the present, comparing the differences and pros and cons. Among them, the competition for general-purpose DA is intensifying. What impact will the upgrade to Dencun in Cancun have?

This article is compiled and organized for reference. For any doubts, please refer to the original text.

On-chain Solution: Proto-Danksharding

Relying entirely on Ethereum's on-chain solution means that Layer2 still uses Ethereum as the data availability layer, reducing the cost of protecting data availability through the Ethereum Cancun upgrade.

Major Expectations for Ethereum 2024: Deployment of the Dencun Cancun upgrade, aiming to deploy the test network in January

The Cancun upgrade will introduce Proto-Danksharding EIP-4844, which is Ethereum's solution to lower data storage costs. It will introduce a new transaction format — Blob, where transaction data uploaded on Layer2 will be temporarily stored in Blob format on the Ethereum consensus layer, bringing cheaper data availability to L2 and deleting it after a certain period.

The Ethereum Foundation hopes to reduce the data storage costs of Layer2 through this means, preventing it from using other off-chain solutions. However, things seem to be not as smooth as expected.

Off-chain Solution

The off-chain solutions no longer treat Ethereum as the DA layer and instead seek more economical ways to obtain data availability. Based on the trade-off between decentralization and security, off-chain solutions can be divided into five types:

• Plasma
• Validium
• Data Availability Committee DAC
• Volition
• Generic DA Solutions

Plasma

Following Ethereum's announcement of a scaling roadmap centered around Rollups, Plasma's scaling solution has now been abandoned by Ethereum.

The principle of Plasma is to periodically upload the transaction information hash tree on the network and use fraud proofs to ensure asset security. The complete transaction records are not stored on Ethereum but by using off-chain means.

Vitalik advocates for Plasma revival combined with ZK-SNARKs to effectively enhance development experience and security.

Validium

Like Plasma, Validium is gradually losing interest. Since the transaction data released to the off-chain in Validium is managed by a centralized operator, it is considered a highly centralized data availability layer solution.

Under the Validium mode, although transaction privacy is greatly protected, data availability costs are minimized, and the risk is also the highest. If there is a failure or malicious behavior by the off-chain operator, users' funds will be irrecoverable.

Data Availability Committee DAC

To reduce the single point of failure risk brought by a single operator, most past Validium designs are paired with a Data Availability Committee, DAC, to enhance data security.

DAC is similar to a consortium chain, composed of multiple authoritative or trusted node members, saving copies of transaction data and publicly disclosing data in case of operator failure or malicious behavior, facilitating proof of user asset ownership and fund extraction.

Although the operating costs of DAC are relatively low, from a security perspective, a small DAC of 8 to 10 people is still prone to private key theft or collective malicious behavior, posing significant risks to on-chain funds.

Volition

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

For example, in a DEX built on Volition, users can control multiple accounts, transfer assets to off-chain data accounts when needed for frequent and inexpensive transactions, and then transfer the assets back to on-chain data accounts after the transaction is completed.

Therefore, compared to simple Validium, Volition can inherit some security of Ethereum while maintaining the low cost and high efficiency advantages of off-chain.

Generic DA Solutions

There is also a category of generic DA solutions that provide data availability for Ethereum's Layer2, serving more blockchains without being limited to Ethereum. Examples include EigenDA, Celestia, Avail, etc.

From some perspectives, these decentralized system-based data storage solutions are actually variants of Validium, which is why Vitalik also stated that if the data availability layer relies on such external decentralized systems, then the network is also Validium.

Cancun Upgrade | V God agrees that some products should use Validiums instead of Rollups

Although the technical implementations of generic DA solutions differ, the overall idea is to enhance the security of the data availability layer to achieve public chain-level security. Therefore, they usually have their own verification nodes, block producers, and consensus mechanisms, just without smart contracts and virtual machines.

With higher security and decentralization, it is no wonder that generic DA is considered the most promising off-chain data storage method currently.

Viewpoint | DA competition for data availability layers will present diversified development

Technology Evolves Rapidly with Environmental and Financial Changes

With the changes in Ethereum's development roadmap centered around Rollups and the recent Cancun upgrade, the landscape of future mainstream data storage methods continues to be influenced. Technological iterations are advancing rapidly, and there may still be many innovations to be explored in blockchain data storage methods.

Ethereum releases its 2024 roadmap, continuing to advance towards a global settlement layer

In addition, every project hopes to play a key role in the Web3 world, and the value of being the DA layer of the mainstream network is immense, continually driving industry progress.

Under the influence of changing development environments and commercial interests, it is not surprising that DA has been so hot in recent years. There are still many variables and spaces for how the market will develop in the end, which is worth continuously observing the future changes in the industry.