On-chain data availability has become an increasingly common topic as Ethereum continues to scale.
Today, Ethereum developers are looking at where and how data should be stored on blockchain networks as they work towards resolving the so-called blockchain trilemma, referring to the tradeoffs between security, scalability and decentralization.
In crypto, data availability refers to the concept that data that is stored on a network is accessible and retrievable by all network participants.
On Ethereum layer-1, the network’s nodes download all the data in each block, making it difficult for invalid transactions to be executed.
Although this can guarantee security, this process can be relatively inefficient — asking a network node to verify and store all data in a block can drastically reduce throughput and hinder blockchain scalability.
Ethereum layer-2 scaling solutions are designed to resolve this problem.
One popular solution today is the optimistic rollup, such as Arbitrum and Optimism. Optimistic rollups are “optimistic” in nature as they assume transactions…