Blockchain Driven Privacy Preserving Contact Tracing Framework in Pandemics

TL;DR

This paper introduces a lightweight, fully decentralized blockchain framework for privacy-preserving contact tracing in pandemics, utilizing novel verification and consensus mechanisms to improve accuracy, timeliness, and security.

Contribution

It proposes a new blockchain-based contact tracing framework with RSA-based verification and a reputation-based delegated proof of stake consensus, addressing gaps in existing designs.

Findings

Achieves over 96% contact recording accuracy with 60% verification failure probability.

Demonstrates robustness and attack resistance in simulated contact scenarios.

Ensures timely reporting and maintains decentralization through novel consensus and incentive mechanisms.

Abstract

Contact tracing has been proven an effective approach to control the virus spread in pandemics like COVID-19 pandemic. As an emerging powerful decentralized technique, blockchain has been explored to ensure data privacy and security in contact tracing processes. However, existing works are mostly high-level designs with no sufficient demonstration and treat blockchain as separate storage system assisting third-party central servers, ignoring the importance and capability of consensus mechanism and incentive mechanism. In this paper, we propose a light-weight and fully third-party free Blockchain-Driven Contact Tracing framework (BDCT) to bridge the gap. In the BDCT framework, RSA encryption based transaction verification method (RSA-TVM) is proposed to ensure contact tracing correctness, which can achieve more than 96\% contact cases recording accuracy even each person has 60\% probability of failing to verify the contact information. Reputation Corrected Delegated Proof of Stake (RC-DPoS) consensus mechanism is proposed together with the incentive mechanism, which can ensure timeliness of reporting contact cases and keep blockchain decentralized. A novel contact tracing simulation environment is created, which considers three different contact scenarios based on population density. The simulation results demonstrate the effectiveness, robustness and attack resistance of RSA-TVM and RC-DPoS in the proposed BDCT.