Data availability is a fundamental bottleneck in modern blockchain networks. Most blockchain systems rely on a full-replication model, which requires downloading of a full block to verify its availability. This model does not scale with block size because every node must handle large volumes of data, leading to slower block propagation, duplicated data transfer, and longer consensus agreement. This issue is well-known in Ethereum, where layer-2 rollups publish data directly into the chain. To overcome, Ethereum adopts Data Availability Sampling (DAS) to let nodes keep only a small fragment of the data while still ensuring availability. Prior work on DAS has focused on cryptographic foundations. Meanwhile, the peer-to-peer network layer that provides Byzantine-tolerant and scalable mechanisms for discovery and routing of DAS fragments is underexplored. We propose CDA, a new design for DAS based on coded distributed arrays that leverages network coding to ensure both robustness and efficiency. Our evaluation study compares CDA to RDA, the latest DAS development of Ethereum, showing an improvement of several times better.

翻译：数据可用性是现代区块链网络中的一个基础瓶颈。大多数区块链系统依赖于全复制模型，该模型需要下载完整区块才能验证其可用性。这种模型无法随区块大小扩展，因为每个节点必须处理大量数据，导致区块传播变慢、数据传输重复、共识达成时间延长。这一问题在以太坊中尤为突出，其中二层汇总直接将数据发布到链上。为了克服这一挑战，以太坊采用了数据可用性采样，让节点仅保留数据的一小部分，同时仍能确保可用性。先前关于DAS的研究主要集中在密码学基础上。与此同时，提供拜占庭容错且可扩展的DAS片段发现和路由机制的P2P网络层尚未得到充分探索。我们提出了CDA，一种基于编码分布式阵列的DAS新设计，该设计利用网络编码来确保鲁棒性和效率。我们的评估研究将CDA与以太坊最新的DAS方案RDA进行了比较，结果显示CDA的性能提升了数倍。