PIR-DSN: A Decentralized Storage Network Supporting Private Information Retrieval

TL;DR

PIR-DSN is a novel decentralized storage network protocol that integrates private information retrieval to enhance user privacy during file access, ensuring security and efficiency in Web 3.0 environments.

Contribution

It introduces a secure mapping method and Byzantine-robust PIR mechanism, enabling private, verifiable, and efficient file retrieval in decentralized storage networks.

Findings

Achieves comparable upload and deletion overheads to existing systems.

Maintains throughput despite additional PIR computational costs.

Demonstrates practical viability for privacy-sensitive applications.

Abstract

Decentralized Storage Networks (DSNs) are emerging as a foundational infrastructure for Web 3.0, offering global peer-to-peer storage. However, a critical vulnerability persists: user privacy during file retrieval remains largely unaddressed, risking the exposure of sensitive information. To overcome this, we introduce PIR-DSN, the first DSN protocol to integrate Private Information Retrieval (PIR) for both single and multi-server settings. Our key innovations include a novel secure mapping method that transforms sparse file identifiers into compact integer indexes, enabling both public verifiability of file operations and efficient private retrieval. Furthermore, PIR-DSN guarantees Byzantine-robust private retrieval through file replication across multiple miners. We implement and rigorously evaluate PIR-DSN against three prominent industrial DSN systems. Experimental results demonstrate that PIR-DSN achieves comparable overhead for file upload and deletion. While PIR inherently introduces an additional computational cost leading to higher retrieval latency, PIR-DSN maintains comparable throughput. These findings underscore PIR-DSN's practical viability for privacy-sensitive applications within DSN environments.