Data Availability
Also known as: Blockchain Data Integrity, Availability Layer, Data Availability Proof
The assurance that all necessary blockchain data is accessible for verifying blocks and maintaining network consensus.
Data availability in blockchain refers to the guarantee that all required data—particularly block contents—is accessible to network participants for validation and synchronization. If a block producer hides data, other nodes cannot verify transactions or execute the block, compromising consensus. This issue becomes critical in Layer 2 rollups and sharded blockchains. Solutions like data availability layers (e.g., Celestia), erasure coding, and fraud proofs aim to ensure that data can be reconstructed and verified. Data availability is a cornerstone of secure scaling and decentralized validation.