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Guide to EigenDA

May 1, 2024

Coinbase is happy to announce that EigenDA will be the first AVS on EigenLayer that our Operator will support. If you’ve restaked ETH or LSTs on EigenLayer, visit our delegation guide to learn how to delegate to our Operator.

Intro to EigenDA

EigenDA is a protocol that provides an efficient and cost-effective way for rollups to package and send their transaction data to Ethereum’s consensus layer, where validators need it to verify the blocks containing the rollups’ commitments. Another way to think about it is as a high-throughput data availability (DA) service for rollups.

DA solutions like EigenDA seek to help solve Ethereum’s scaling problem, caused by congestion and high costs associated with the increasing amount of transaction data originating on mainnet and from rollups and other L2s. 

EigenDA is built atop EigenLayer, a restaking protocol on Ethereum that enables developers to leverage Ethereum’s validator set and economic security to avoid bootstrapping their own decentralized network. As such, it’s considered an Actively Validated Service, or AVS. (EigenDA and EigenLayer are creations of the same team: EigenLabs.) For more, read our EigenLayer Protocol Guide.

As an AVS, EigenDA recruits Operators on EigenLayer, which have staked ETH delegated to them, to maintain nodes on its behalf in return for rewards (though EigenLayer has yet to activate rewards). Think of Operators as similar to validators on a network. Coinbase’s Operator is maintaining a node within EigenDA’s network.  

To better understand the innovation behind EigenDA, it’s important to understand the problem it’s trying to solve. This means diving a bit deeper into data availability, or DA.

The DA problem

Validators on a proof-of-stake blockchain like Ethereum need to be able to verify all the transactions included in a proposed block. Data availability (DA) is the guarantee that all that transaction data is available for all network participants, including the validators that need to verify the next block. 

Validators on Ethereum have traditionally downloaded and stored all transaction data. This makes sense, as any network participant should be able to verify the current state of the blockchain by reviewing historic transactions — but it’s not scalable. As the number of transactions grows, the amount of associated data needing to be passed around and stored strains the network. 

Enter rollups. 

Rollups (sometimes referred to as L2s) help Ethereum scale by moving transactions offchain, bundling them, and committing the compressed data to mainnet in order for validators to verify the transactions. Rollups have been doing this using “calldata” or  the information provided to a smart contract that’s required for the contract to properly execute whatever task it’s doing. 

But as rollups have grown, the network is running into the same DA bottleneck. That’s because even though rollups bundle and compress transaction data, validators on Ethereum are still downloading and permanently storing all of it.

Ethereum’s core developer teams are tackling the DA problem. The recent Dencun network upgrade, introduced the first step toward an Ethereum-native DA solution. Specifically, it included EIP-4844 (known as proto-danksharding), which introduced a new transaction type and vehicle (called blobs) that rollups can use to commit their transaction data to the blockchain. Blobs represent dedicated — but temporary — storage space attached to each block. 

But proto-danksharding is not the endgame - it is an intermediate step towards full danksharding. Full danksharding will not only enable rollups to commit their data via blobs to the blockchain, but to also break it up and disperse it among validators so a single node no longer needs to store, even temporarily, all the data flowing in from rollups.

Full danksharding is still a few network upgrades away; however, in the meantime, other protocols have sprung up to focus on scaling DA and offer alternative options to Ethereum’s native DA solution (i.e., proto-danksharding). EigenDA is one of those options.

What does EigenDA do?

EigenDA is inspired by danksharding, the proposed Ethereum-native DA solution, but is different in a few key ways.

Rather than segment a rollup’s data, store the fragments in blobs, and disperse them among validators on Ethereum, EigenDA breaks up the data, disperses the fragments (also called blobs) among its network of Operators on EigenLayer, then committing a cryptographic proof to the Ethereum blockchain that the transactions are authentic and available to be retrieved if necessary. EigenDA only requires nodes to download small amounts of data instead of entire blobs and uses validity proofs to enable nodes to verify correct coding of data. 

Another way to think about it is that EigenDA decouples DA and consensus, allowing it to achieve much higher throughput than currently possible. Ethereum’s monolithic architecture has DA and consensus tightly coupled, requiring validators to attest to blob availability, as well as ordering the blobs in each block, which is a complex process that causes consensus lags. EigenDA removes the complexity around ordering.

EigenDA’s solution is scalable since its write throughput scales linearly with its number of Operators. The number of Operators also determines EigenDA’s level of decentralization and security — the more operators it has, the more decentralized and secure it will be. As of April 24, 2024, EigenDA has 98 operators and ~2.1M ETH in TVL, which is close to $7 billion. 

While it’s built on EigenLayer, EigenDA can also introduce what’s known as a “dual quorum,” which is where two separate quorums can be required to attest to DA — ETH restakers (via EigenLayer Operators) and a rollup’s native stakers. Both quorums are treated as independent and redundant, which means both would need to fail before EigenDA fails.

EigenDA’s architecture

There are three components in EigenDA’s architecture: Operators (like Coinbase), the disperser, and retrievers. 

Operators

Operators are independent third parties that run EigenDA's node software. Operators are registered on EigenLayer and opt in with the staked ETH and LSTs delegated to them to maintain nodes on behalf of AVSs like EigenDA. To delegate to our Operator, check out our delegation guide

Operators store blobs associated with valid storage requests, which are when fees are paid and the blob chunk is verified against the provided KZG commitment and proof. When successfully verified, the Operator stores the blob and signs a message to be sent to the disperser. 

Disperser

The disperser is an untrusted service hosted by EigenLabs, the creator of both EigenLayer and EigenDA. It is the interface between EigenDA clients (i.e., rollups), operators, and contracts.

The disperser takes dispersal requests from EigenDA clients and generates a proof for each blob chunk. The disperser then sends all the necessary information/data to Operators who return signatures. The disperser aggregates these signatures and uploads them to the EigenDA manager contract on Ethereum. 

Retriever

The retriever is a service that queries EigenDA Operators for blob chunks, verifies the blobs are accurate, and reconstructs the original blob.

Source: EigenDA Overview

What Operators need to know

To secure an AVS like EigenDA, Operators will opt in to a smart contract that dictates the rewards it will receive for securing the network, as well as the slashing penalties in place to deter bad actors. However, as of now (April 25, 2024), EigenLayer has not yet activated rewards or slashing.  

For more information on EigenDA, refer to EigenLayer’s blog post on EigenDA. If you’re an optimistic rollup interested in integrating EigenDA, refer to EigenLayer’s docs on rollup integration.

Conclusion

By decoupling data availability assurances from consensus duties, EigenDA offers an innovative approach to tackling Ethereum's DA challenges, and a scalable solution to support the blockchain's ambitious roadmap.

Of course, as a new protocol, EigenDA and its underlying technologies still face ongoing real-world testing and review. As one of the Operators supporting EigenDA via our participation in the EigenLayer protocol, Coinbase looks forward to continuing our support of this pioneering approach to data availability and extending Ethereum's capabilities in an open and sustainable manner.

Disclaimer

This document and the information contained herein is not a recommendation or endorsement of any digital asset, protocol, network, or project. However, Coinbase may have, or may in the future have, a significant financial interest in, and may receive compensation for services related to one or more of the digital assets, protocols, networks, entities, projects, and/or ventures discussed herein. The risk of loss in cryptocurrency, including staking, can be substantial and nothing herein is intended to be a guarantee against the possibility of loss.This document and the content contained herein are based on information which is believed to be reliable and has been obtained from sources believed to be reliable, but Coinbase makes no representation or warranty, express, or implied, as to the fairness, accuracy, adequacy, reasonableness, or completeness of such information, and, without limiting the foregoing or anything else in this disclaimer, all information provided herein is subject to modification by the underlying protocol network. Any use of Coinbase’s services may be contingent on completion of Coinbase’s onboarding process and is Coinbase’s sole discretion, including entrance into applicable legal documentation and will be, at all times, subject to and governed by Coinbase’s policies, including without limitation, any applicable terms of service and privacy policy, as may be amended from time to time.