Data Availability
The confidence that the data needed to verify a block was actually published and is available to network participants.
- glossary
Data availability (DA) is the confidence a network can have that the data required to verify a block was actually published and is available to anyone who wants to check it—not just summarized or promised. It matters most for rollups and light clients, which rely on strong data guarantees without downloading and storing every byte of transaction data themselves; a rollup operator that posts an invalid state commitment without making the underlying data available could go undetected. Data availability sampling (DAS) solves this efficiently: a light node downloads only small, randomly selected pieces of a block's data and, using erasure coding, can still become confident the full data was published. Dedicated DA layers such as Celestia and EigenDA now let rollups post their data somewhere cheaper than Ethereum mainnet while still getting a data-availability guarantee. Rollups that use an external DA layer instead of posting to layer 1 are sometimes called validiums or optimiums. For tokenized domains, the DA layer a rollup chooses is part of what determines how strongly a domain NFT's ownership history is anchored and verifiable.
Related keywords
- data availability
- da
- data availability sampling
- das
- celestia
- eigenda
- rollup data
Contributors
Namefi is a collective of engineers, designers, and operators who obsess over building tools that make managing your onchain domain names effortless.
Victor Zhou is a technology founder and standards editor focused on digital identity and trust. He founded Namefi, edits Ethereum Improvement Proposals, and previously led smart-contract architecture work at Google Labs.
His work sits at the intersection of naming, ownership, and the systems people use to establish identity online. That perspective makes him especially interested in the way names move between personal meaning, public recognition, and digital infrastructure.
For Namefi, Victor edits and writes about domains as durable digital identity: how names become ownable onchain assets, how tokenization changes custody and trust, and what naming can learn from the systems people use to establish identity online.