English

DatashareNetwork: A Decentralized Privacy-Preserving Search Engine for Investigative Journalists

Cryptography and Security 2020-09-01 v2

Abstract

Investigative journalists collect large numbers of digital documents during their investigations. These documents can greatly benefit other journalists' work. However, many of these documents contain sensitive information. Hence, possessing such documents can endanger reporters, their stories, and their sources. Consequently, many documents are used only for single, local, investigations. We present DatashareNetwork, a decentralized and privacy-preserving search system that enables journalists worldwide to find documents via a dedicated network of peers. DatashareNetwork combines well-known anonymous authentication mechanisms and anonymous communication primitives, a novel asynchronous messaging system, and a novel multi-set private set intersection protocol (MS-PSI) into a *decentralized peer-to-peer private document search engine*. We prove that DatashareNetwork is secure; and show using a prototype implementation that it scales to thousands of users and millions of documents.

Keywords

Cite

@article{arxiv.2005.14645,
  title  = {DatashareNetwork: A Decentralized Privacy-Preserving Search Engine for Investigative Journalists},
  author = {Kasra EdalatNejad and Wouter Lueks and Julien Pierre Martin and Soline Ledésert and Anne L'Hôte and Bruno Thomas and Laurent Girod and Carmela Troncoso},
  journal= {arXiv preprint arXiv:2005.14645},
  year   = {2020}
}
R2 v1 2026-06-23T15:54:48.912Z