ISTIRDA: An Efficient Data Availability Sampling Scheme for Lightweight Nodes in Blockchain

Lightweight nodes are crucial for blockchain scalability, but verifying the availability of complete block data puts significant strain on bandwidth and latency. Existing data availability sampling (DAS) schemes either require trusted setups or suffer from high communication overhead and low verification efficiency. This paper presents ISTIRDA, a DAS scheme that lets light clients certify availability by sampling small random codeword symbols. Built on ISTIR, an improved Reed–Solomon interactive oracle proof of proximity, ISTIRDA combines adaptive folding with dynamic code rate adjustment to preserve soundness while lowering communication. This paper formalizes opening consistency and prove security with bounded error in the random oracle model, giving polylogarithmic verifier queries and no trusted setup. In a prototype compared with FRIDA under equal soundness, ISTIRDA reduces communication by 40.65% to 80%. For data larger than 16 MB, ISTIRDA verifies faster and the advantage widens; at 128 MB, proofs are about 60% smaller and verification time is roughly 25% shorter, while prover overhead remains modest. In peer-to-peer emulation under injected latency and loss, ISTIRDA reaches confidence more quickly and is less sensitive to packet loss and load. These results indicate that ISTIRDA is a scalable and provably secure DAS scheme suitable for high-throughput, large-block public blockchains, substantially easing bandwidth and latency pressure on lightweight nodes.