How is data availability proven?

[TimTinkers]

Hello, I've read the documentation and in this diagram I feel I understand everything except the data availability.

The OP Stack is running, presumably its op-batcher is still happily filling up blobs, and op-succinct is generating validity proofs for confirmation on L1. But how is the data from those blobs confirmed as part of the proof? I'm missing the link that takes this from validium to rollup.

Thank you!

[Thegaram]

I just came here to ask this question when I saw your issue.

From the values passed to the verifier, the only one that can capture DA is _l1BlockHash.

My guess is that BlobProvider verifies that the raw data matches the blob hash, then ChainProvider verifies that the blob hashes belong to a certain L1 block hash, then we verify that these blocks chain up to _l1BlockHash.

It seems that all data needed for proving is passed here, and verified here using InMemoryOracle.

[ratankaliani]

That's correct @Thegaram! In the future, when Optimism moves to using nonces for the SystemConfig and DepositTransaction's, this derivation will become easier to prove.