Decentralized storage networks (DSNs) are storage systems powered by permissionless nodes. Data placement in DSNs must tolerate not only storage-device failures but also adversarial behavior that targets data availability. Byzantine nodes introduce unique challenges due to collusion and adaptive attacks. They can target specific data blocks by clustering within a block's placement group, reducing the number of rational nodes and weakening failure tolerance. In this work, we propose a global defense against Byzantine nodes across all placement groups. We introduce a node-centric approach that guarantees stable incentives for rational nodes regardless of the number of Byzantine nodes in their placement groups. Building on this approach, we design Vault, a DSN that uses sampling-based data placement with verifiable randomness. Compared with prior DSNs, this placement strategy allows Vault to scale simultaneously in storage volume, on-chain footprint, and Byzantine tolerance. Our preliminary results show that Vault achieves the desired availability with scalable storage overhead while maintaining scalable fault tolerance.

翻译：去中心化存储网络（DSNs）是由无许可节点驱动的存储系统。在DSN中，数据放置不仅要容忍存储设备故障，还需应对针对数据可用性的恶意行为。拜占庭节点因合谋与自适应攻击而带来独特挑战：它们可通过在数据块的放置组内聚集，减少理性节点数量并削弱容错能力，从而针对特定数据块实施攻击。本文提出一种跨所有放置组的全局拜占庭防御机制。我们引入一种以节点为中心的方法，确保无论放置组内存在多少拜占庭节点，理性节点都能获得稳定的激励。基于此方法，我们设计了Vault——一种通过可验证随机性实现基于采样数据放置的DSN。与现有DSN相比，该放置策略使Vault能在存储容量、链上足迹及拜占庭容错能力三个维度上实现同步扩展。初步结果显示，Vault在保持可扩展容错能力的同时，以可扩展的存储开销实现了预期的可用性目标。