### Relation between EigenDA and Ethereum

EigenDA isn’t a separate blockchain, it’s an Actively Validated Service (AVS) built on top of EigenLayer, and all of its security/consensus ultimately anchors to Ethereum. Here’s how:

#### 1. Validator set & stake anchoring

- EigenDA validators are Ethereum validators who have restaked ETH (or liquid staking tokens) into EigenLayer.
- Their stake lives in Ethereum smart contracts (EigenPod, EigenLayer contracts).
- This means: if they misbehave (e.g., sign for chunks they don’t store), they can be slashed on Ethereum.
- So Ethereum enforces cryptoeconomic security for EigenDA, without EigenDA running its own consensus chain.

#### 2. Quorum membership

- Who counts as an EigenDA validator, and how much weight they carry, is tracked on Ethereum.
- A contract on Ethereum keeps the mapping of **validator** → **stake** → **quorum membership**.
- When validators churn (join/leave), the Churner module in EigenDA updates membership based on what’s finalized on Ethereum.
- So Ethereum is the source of truth for the EigenDA validator set.

#### 3. Data availability certificates (DA certs)

- When a blob is dispersed:
- Validators sign a header commitment (KZG commitment to encoded blob).
- Once enough stake has signed (≥ confirmation threshold), a DA certificate is formed.
- That DA cert includes quorum information, which Ethereum contracts can verify:
- Was this cert signed by the right validator set?
- Did it reach the quorum thresholds defined in EigenLayer/Ethereum?

This is why rollups using EigenDA can post only the certificate on Ethereum, instead of the full blob. Ethereum smart contracts then check the cert against the registered EigenDA verifier contracts (e.g., **CertVerifierV3** + Router).

#### 4. Ethereum as final settlement layer

- Rollups (Arbitrum, OP Stack, etc.) that integrate EigenDA **settle disputes and proofs on Ethereum**.
- If a sequencer lied about data availability, challengers can use Ethereum contracts to:
- Point to the certificate,
- Prove (using quorum signatures, slashing conditions, etc.) whether the blob really was dispersed,
- And trigger slashing on validators if misbehavior is proven.

#### To summarise
- **EigenDA runs off-chain for scalability** (erasure coding, relays, validators store blobs).
- Ethereum enforces accountability:
- Validator stake lives on Ethereum.
- Validator membership is tracked on Ethereum.
- DA certificates are verified on Ethereum.
- Misbehavior is punished on Ethereum.

So: EigenDA = scalable off-chain DA layer, secured by Ethereum’s stake & contracts.