The data availability (“DA”) problem asks this question: how can we ensure that all network participants can access the data of a newly proposed block? It emerged as a necessity alongside rollups and the modular blockchain paradigm.
Dedicated DA layers have largely emerged in response to the increasing costs of posting data directly to major Layer-1s (“L1s”), especially Ethereum.
This report is part of our technical series. We feature major DA players and explain the technical primitives underpinning their solutions and their anticipated impacts on products and future positioning.
Celestia and Avail (and likely Danksharding) rely on data availability sampling (“DAS”). With DAS, light clients contribute to security very efficiently. A dozen or so DAS operations give over 99.9% confidence that all data is available. This results in very high security, where data availability is guaranteed as long as 1-of-n or even 0-of-n full nodes are honest.
Among the protocols discussed in this report, EigenDA is unique in its use of a dispersal protocol. This may enable better scalability as individual nodes’ storage requirements drop as more nodes join the network. The downside is that security requires a majority or supermajority of honest nodes.
Avail and EiganDA (and Danksharding) use Kate-Zaverucha-Goldberg (“KZG”), which has useful properties that allow validity proofs to be generated. Avail uses this for faster DA finality and potentially better integration with zk-rollups.
All the above projects use erasure codes extensively. This technique allows protocols to achieve better (often optimal) trade-offs.
In designing these protocols, tradeoffs include scalability, security, and finality speed.
The different protocols featured in this report made different design decisions regarding these trade-offs. This will likely result in persistent differences in cost, security, and finality speed, which may be deciding factors for project teams (although KPI comparisons will likely fluctuate in the short term).
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