An overview of the five factors in modular DA design: Celestia, Avail, and EigenDA - Who is the winner?

Written by: hitesh.eth, Crypto KOL

Compiled by: Felix, PANews

Arbitrum paid about $1980/MB in DA fees last month. Meanwhile, Manta only paid $3.41/MB using Celestia DA. A modular DA layer can save Rollups a significant amount of Gas fees. Celestia, Avail, or EigenDA… who will win the DA battle?

Why is Modular DA Needed?

In monolithic blockchains like Ethereum, data availability (DA) is often part of the design of a single system, and when block space utilization is high, data availability becomes a bottleneck limiting its development. The higher the Gas fees, the worse the user experience.

Ethereum has also recognized the scalability issue over the years and has begun exploring various off-chain scaling solutions. Rollups, especially OP Rollups, have become popular off-chain scaling solutions in recent years, but they still face the problem of excessively high Gas fees when block space demand is high.

Another issue facing Rollups is that they spend nearly 70-90% of their revenue on calling data and storage on Ethereum DA.

A modular data availability layer is one of the potential solutions to reduce DA costs, potentially lowering costs by up to 99%.

This has been validated on Celestia and Manta. By choosing Celestia over Ethereum DA, Manta successfully saved nearly 99% of its DA costs. Although Ethereum is also undergoing significant upgrades that will introduce separate block space for L2 calling data.

It is estimated that calling data costs can be reduced by 5-10 times. But even when comparing Proto Dank Sharding (EIP-4844) with Celestia, Celestia still has at least a 50 times advantage over Blobspace.

The question now is, what design considerations of modular DA like Celestia, Avail, and EigenLayer allow them to reduce the cost of publishing calling data to such low levels?

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

Data Availability Sampling (DAS)

Consensus + DA Assurance

Degree of Decentralization

Scalability

Cost

Data Availability Sampling

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

Modular DAs like Celestia and Avail use technologies 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), allowing Rollups to only publish the relevant parts of the data to the Celestia block, helping to reduce storage and verification costs for light nodes. EigenDA does not use data availability sampling.

Consensus + Data Assurance

When discussing reducing data availability costs, consensus plays its role. It consists of two parts: transactions should be added to blocks more quickly, and the accuracy of transactions should have security guarantees.

Thus, the block finalization time plus the data assurance time will each play a role in optimizing the performance of the DA layer. Celestia uses Tendermint, which is faster in block finalization time and employs anti-fraud designs to ensure transaction accuracy.

On the other hand, Avail uses a hybrid consensus mechanism inherited from the Polkadot SDK (Grandpa and Babe), which has a slower block finalization time compared to Tendermint. However, since Avail also uses KZG commitments for validity proofs, the speed of verifying transaction accuracy is faster than Celestia.

EigenDA uses Ethereum's Casper proof-of-stake consensus, which is slower than the other consensus mechanisms discussed above. EigenDA uses a Data Availability Committee (DAC) for the verification process; DAC is a committee composed of a group of validators responsible for the verification process.

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

Decentralization

The degree of decentralization is one of the most important aspects of design considerations. The degree of decentralization refers to how many validators are protecting the network and the distribution of stakes across the network. Celestia supports up to 100 validators.

Avail uses designated proof-of-stake and supports up to 1000 validators. It can continue to operate even if most full nodes go down, as they are sampled from a p2p network of light nodes. Avail is the only DA layer with a robust fault-tolerance mechanism.

EigenDA is an Active Verification Service (AVS) that shares security from Ethereum validators by re-staking ETH locked on smart contracts. The security guarantees of EigenDA will depend on the amount of ETH re-staked by the number of validators.

Scalability

Modular layers 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 the growing demand. The DAC used by EigenDA is also considered scalable.

Cost

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