Paper 2025/918

The Accidental Computer: Polynomial Commitments from Data Availability

Abstract

In this paper, we show two simple variations of a data availability scheme which enable it to act as a multilinear polynomial commitment scheme over the data in a block. The first variation enables commitments over all of the block's data with zero prover overhead: the data availability construction simply serves both purposes. The second variation allows commitments over subsets of data with nonzero but still concretely small proving costs, since most work is already done during data encoding. This works especially well for blockchains with a high degree of data parallelism, as data-parallel computation is particularly amenable to efficient GKR proofs. Since, in GKR, opening the polynomial commitment contributes significantly to prover costs, our construction enables the prover to reuse work already done by the data availability scheme, reducing—or wholly removing—work associated with the polynomial commitment scheme.