The data availability problem is a central challenge in blockchain systems and lies at the core of the accessibility and scalability issues faced by platforms such as Ethereum. Modern solutions employ several approaches, with data availability sampling (DAS) being the most self-sufficient and minimalistic in its security assumptions. Existing DAS methods typically form cryptographic commitments on codewords of fixed-rate erasure codes, which restrict light nodes to sampling from a predetermined set of coded symbols. In this paper, we introduce a new approach to DAS that modularizes the coding and commitment process by committing to the uncoded data while performing sampling through on-the-fly coding. The resulting samples are significantly more expressive, enabling light nodes to obtain, in concrete implementations, up to multiple orders of magnitude stronger assurances of data availability than from sampling pre-committed symbols from a fixed-rate redundancy code as done in established DAS schemes using Reed Solomon or low density parity check codes. We present a concrete protocol that realizes this paradigm using random linear network coding (RLNC).

翻译：数据可用性问题在区块链系统中是一个核心挑战，也是以太坊等平台面临的可访问性和可扩展性问题的核心。现代解决方案采用多种方法，其中数据可用性采样（DAS）在安全性假设上最为自足和极简。现有的DAS方法通常基于固定速率擦除码的码字形成密码学承诺，这限制了轻节点只能从预定义的编码符号集合中进行采样。本文提出了一种新的DAS方法，该方法通过承诺未编码数据并执行实时编码采样，实现了编码与承诺过程的模块化。由此产生的采样结果表达能力显著增强，使得轻节点在具体实现中能够获得比现有DAS方案（使用里德-所罗门码或低密度奇偶校验码，从固定速率冗余码中采样预承诺符号）高出多个数量级的数据可用性保证。我们提出了一种具体协议，使用随机线性网络编码（RLNC）实现了这一范式。