Polynomial Multiproofs for Scalable Data Availability Sampling in Blockchain Light Clients

2026-04-17

AI Summary

This work addresses the high bandwidth, storage, and verification overheads incurred by blockchain light clients in data availability sampling, where each sampled unit traditionally requires an individual KZG proof. The paper introduces, for the first time, a Polynomial Multi-Proof (PMP) mechanism to this setting, aggregating proofs for multiple sampled units into a single proof over a shared micro-domain. It further redesigns the proof generation, dissemination, retrieval, and verification pipeline within the P2P light client stack. Experimental evaluation on Avail’s modular data availability layer demonstrates that the proposed approach substantially reduces proof size, validator CPU and memory consumption, and infrastructure costs—by up to 45% compared to per-unit baselines—while also uncovering a critical trade-off between aggregation efficiency and security guarantees.

Technology Category

• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust
• Multiagent Systems: Mechanism Design
• Machine Learning: Multi-instance/Multi-view Learning

Application Category

• Security and Privacy: Data transparency and provenance
• Web Mining and Content Analysis: Web data provenance, reliability, and authenticity
• Responsible Web: Data and user privacy-enhancing technologies for the Web

Abstract

Light clients are essential for scalable blockchain systems because they verify data availability without downloading full blocks. In data availability sampling based systems, sampled cells are retrieved from a peer-to-peer network and verified against cryptographic commitments. A common deployment pattern associates each sampled cell with an independent Kate-Zaverucha-Goldberg (KZG) proof, creating substantial cumulative bandwidth, storage, and verification overhead. This paper studies polynomial multiproofs (PMP) as a mechanism for reducing these costs in blockchain light clients. We present a design in which multiple sampled cell evaluations are verified using a single aggregated proof over a shared evaluation micro-domain and describe the corresponding changes to proof generation, dissemination, retrieval, and verification in a peer-to-peer light-client stack. We instantiate and evaluate the design in Avail, a modular data availability layer for blockchains, as a case study. The results show lower proof bytes, lower verifier CPU and memory usage, and deployment-level infrastructure cost reductions of up to 45% relative to a per-cell baseline, while also clarifying the trade-offs introduced by grouped retrieval.

Problem

• data availability sampling
• light clients
• KZG proofs
• blockchain scalability
• proof overhead

Innovation

• Polynomial Multiproofs
• Data Availability Sampling
• Light Clients
• KZG Commitments
• Proof Aggregation