A look at five factors in modular DA design: Celestia, Avail and EigenDA Who is the winner?

Five factors include data availability sampling, consensus + DA guarantee, degree of decentralization, scalability and cost.

Written by: hitesh.eth, crypto KOL

Compiled by: Felix, PANews

Arbitrum paid approximately $1,980/MB in DA fees last month. Meanwhile, Manta only pays $3.41/MB using Celestia DA. The modular DA layer can save a lot of gas fees for Rollups. Celestia, Avail or EigenDA…who will win the DA battle?

Why is modular DA needed?

In a monolithic blockchain like Ethereum, data availability (DA) is usually part of the design of a single system, and when block space utilization is high, data availability will become a bottleneck limiting its development. The higher the gas fee, the worse the user experience.

Ethereum has also been aware of the expansion problem over the years and began to explore various off-chain expansion solutions. Rollups, especially OP Rollups, have become a popular off-chain expansion solution in recent years, but they still face the problem of excessive gas fees when the demand for block space is high.

Another problem faced by Rollups is that they spend almost 70-90% of their revenue on calling data and storage of Ethereum DA.

One potential solution for reducing DA costs is the modular data availability layer, which can reduce costs by up to 99%.

This has been proven with Celestia and Manta. Manta managed to save nearly 99% of DA costs by choosing Celestia instead of Ethereum DA. Although Ethereum is also undergoing a major upgrade, a separate block space will be introduced for L2 call data.

It is estimated that the cost of calling data can be reduced by 5-10 times. But even comparing Proto Dank Sharding (EIP-4844) to Celestia, Celestia still beats Blobspace by at least a 50x reduction.

The question now is, what factors were taken into consideration in the design of modular DAs like Celestia, Avail and EigenLayer that enable them to reduce the cost of calling data publishing to such a low level?

There are many factors that affect the overall performance and cost of the DA layer. Crypto KOL hitesh.eth believes that the following five are the most important:

• Data Availability Sampling (DAS)
• Consensus + DA guarantee
• Degree of decentralization
• Expansion capabilities
• cost

Data availability sampling

In Ethereum DA, nodes traverse all the data of a block to check whether the data is available, which not only takes a lot of time but also increases the cost. In data availability sampling, light nodes verify the availability of data without downloading the data.

Modular DAs like Celestia and Avail use techniques such as erasure coding to split data into small shards and allow light nodes to randomly select a subset of shards for download and verification.

Celestia also uses Namespaced Merkle trees (NMT), which allows Rollups to publish only relevant parts of the data to Celestia blocks, helping to reduce light node storage and verification costs. EigenDA does not use data availability sampling.

Consensus + Data Guarantee

Consensus comes into its own when talking about reducing data availability costs. It has two parts: transactions should be added to blocks faster, and there should be security guarantees about the accuracy of transactions.

Therefore, the block final confirmation time plus the data guarantee time will play their respective roles in optimizing the performance of the DA layer. Celestia uses Tendermint, which is faster in terms of block final confirmation time, and also uses fraud-proof design to determine the accuracy of transactions.

Avail, on the other hand, uses a hybrid consensus mechanism (Grandpa and Babe) inherited from the Polkadot SDK, and its block final confirmation time is slower compared to Tendermint. However, because Avail also uses KZG commitments for validity proof, it can verify the accuracy of transactions faster than Celestia.

EigenDA uses Ethereum’s Casper proof-of-stake consensus, which is slower than the other consensus discussed above. EigenDA uses DAC for the verification process; DAC is a committee composed of a group of verifiers responsible for the verification process.

Data Availability Committee (DAC) saves verification time, but also introduces centralization risks. Using DAC can also effectively reduce DA costs, as demonstrated by Metis and other effectiveness solutions.

Decentralization

The degree of decentralization is one of the most important aspects of design factors. The degree of decentralization refers to how many validators are protecting the network and the distribution of interests on the entire network. Celestia supports up to 100 validators.

Avail uses designated proof-of-stake and supports up to 1,000 validators. Even if a majority of full nodes go down, they can remain running because they are sampling from the p2p network of light nodes. Avail is the only DA layer with strong fail-safe mechanisms.

EigenDA is an Active Validation Service (AVS) that shares security from Ethereum validators through locking and staking ETH on smart contracts. EigenDA’s security guarantee will depend on the number of validators and the amount of ETH staked.

Expansion capabilities

The modular layer should have the ability to dynamically scale block sizes as demand increases. Celestia and Avail use large blocks, data availability sampling, and light nodes to meet growing demand. The DAC used by EigenDA is also considered scalable.

cost

The cost of a modular DA depends on the various factors discussed above. Celestia DA is now online and currently charges $3.41/MB for Manta; the cost will vary based on TIA prices. Avail and EigenDA are not yet online, and NEAR DA has the lowest cost.