L1 Data Posting

Definition ∞ L1 data posting refers to the process where Layer 2 scaling solutions, such as rollups, submit compressed transaction data or validity proofs to the underlying Layer 1 blockchain. This action ensures the security and data availability of Layer 2 operations by anchoring them to the more secure and decentralized Layer 1 network. It is a fundamental step in maintaining the integrity of off-chain computations.
Context ∞ The cost and efficiency of L1 data posting are significant factors determining the scalability and economic viability of Layer 2 solutions. Debates frequently concern optimizing data compression techniques and exploring new data availability layers to reduce these costs. The upcoming EIP-4844 upgrade on Ethereum specifically aims to make L1 data posting more affordable through the introduction of temporary data blobs.