Celestia serving as off-chain DA for Ethereum rollups 🧵
The main reliance that rollups have on L1 is the cost of calldata and its data throughput. While Ethereum is in the process of implementing its sharding solution, rollups should have a source of cheap data…
and high data throughput to alleviate some of their near-term scaling bottlenecks. While transaction fees can become cheaper when amortized among a larger batch, there is a point at which the fee decline reaches diminishing returns.
This is where volitions and validiums come to alleviate the problem. Volitions are a type of zkRollup that give users the option to post their transaction data on-chain or off-chain. Similarly, a validium is a zkRollup construction that only has off-chain data availability.
What Celestia can supply to volitions and validiums is a source of cheap and scalable data availability that allows them to provide cheaper transactions to their users.
How this would work is the result of the Quantum Gravity Bridge.
blog.celestia.org/celestiums/
When transactions would be submitted by the validium to Celestia, the validators would check data is available and come to consensus on ordering to publish it to the network. To ensure that the Ethereum verifier contract is aware that data is available on Celestia….
a Merkle root of available data would be signed by 2/3 of the validator set. The signatures for the data would then be sent to a DA contract on the gravity bridge that interacts with the Ethereum verifier contract.
Once the DA contract has received and verified the signatures from the validator set the Ethereum verifier contract would check the signatures attesting to data availability that correspond to the validity proof it verified.