Rollup Data Availability

Rollup data availability is the requirement that the transaction data processed by a Layer 2 solution must be accessible to the public so that the state can be verified. Even though rollups perform execution off-chain, they must prove that their operations are valid, which requires publishing the underlying data to the Layer 1 chain.

If this data is not available, the system could be manipulated, undermining the security of the entire protocol. Ensuring this availability is a major cost and technical hurdle, often requiring specialized data availability layers or protocols.

It is a critical component of the modular blockchain thesis, where different layers handle execution, settlement, and data storage. Mastering this concept is vital for understanding the scalability and security trade-offs of modern Layer 2 solutions.