NC-DHT: a Robust and Anonymous DHT for Blockchain Systems

Abstract

Distributed Hash Tables (DHT) is used for achieving robust routing and overlay for most Blockchain systems. In other words, DHT supports communication in a wide spectrum of Web3 and Blockchain applications, such as data sharing, content distribution, and distributed search engines. The decentralized nature of DHT introduces security and privacy vulnerabilities. Significant efforts have been devoted to making DHT more robust and augmenting DHT’s privacy guarantees. This paper proposes a novel design, namely NC-DHT, which has two main features: (i) NC-DHT tolerates Byzantine nodes, and (ii) NC-DHT provides initiator anonymity, query unlinkability and target privacy. To the best of our knowledge, NC-DHT is the first DHT that supports all these important features, which makes it suitable as an overlay for Blockchains. NC-DHT relies on a novel integration of quorum topology and network coding-based techniques.