BlockTorrent: A Blockchain Enabled Privacy-Preserving Data Availability Protocol for Multi-stakeholder Scenarios

As industries across the globe continue to digitize their processes, the need for a mechanism to share private data between multiple stakeholders is becoming increasingly apparent. However, sharing data poses challenges around privacy and accessibility, particularly in the event of disputes between stakeholders with a shared interest, such as a supply chain. Auditors currently rely on stakeholders' compliance in order to verify data. Malicious parties may falsify the data before passing it onto the auditor. Using supply chains as a case study we present BlockTorrent, a protocol to address these challenges and help facilitate data sharing between supply chain participants. BlockTorrent allows participants to securely share their data in near real-time with other participants without the risk of information leakage or allowing the falsification of data, whilst guaranteeing data availability for auditors. This is achieved using a novel combination of distributed storage and on-chain secret sharing. This paper provides an implementation and evaluation of BlockTorrent, highlighting its performance and a security discussion. Lastly, we provide a discussion on the privacy challenges that were considered when designing BlockTorrent.