Data Availability
Whether the data needed to verify a blockchain's state is actually accessible to the network.
Data availability refers to whether the underlying transaction data needed to verify a blockchain's current state is actually published and accessible, not just a summary or proof of it.
This matters especially for Layer 2 rollups: if transaction data isn't genuinely available, independently reconstructing account balances or challenging an incorrect state becomes difficult or impossible.
Examples
- A rollup posting full transaction data to its base chain is prioritizing data availability over cost savings.
- Data availability is a core design consideration distinguishing different Layer 2 scaling approaches.
Learn more
The Layer 2 Scaling Landscape
Read the research article
Data Availability Sampling
Read the Data Availability Sampling glossary definition
Sovereign Rollup
Read the Sovereign Rollup glossary definition
Proto-Danksharding (EIP-4844)
Read the Proto-Danksharding (EIP-4844) glossary definition
Data Availability Committee (DAC)
Read the Data Availability Committee (DAC) glossary definition