CoAvoid: Secure, Privacy-Preserved Tracing of Contacts for Infectious Diseases

TL;DR

CoAvoid is a decentralized contact tracing system that enhances privacy and security by combining GPS and BLE with obfuscation techniques, achieving high efficiency and resistance to attacks.

Contribution

It introduces a privacy-preserving contact tracing approach that integrates GPS and BLE, utilizing fuzzification and obfuscation to protect sensitive data while maintaining dependability.

Findings

Reduces data upload by at least 90% compared to existing apps

Resists wormhole and replay attacks effectively

Demonstrates good efficacy and security in evaluations

Abstract

To fight against infectious diseases (e.g., SARS, COVID-19, Ebola, etc.), government agencies, technology companies and health institutes have launched various contact tracing approaches to identify and notify the people exposed to infection sources. However, existing tracing approaches can lead to severe privacy and security concerns, thereby preventing their secure and widespread use among communities. To tackle these problems, this paper proposes CoAvoid, a decentralized, privacy-preserved contact tracing system that features good dependability and usability. CoAvoid leverages the Google/Apple Exposure Notification (GAEN) API to achieve decent device compatibility and operating efficiency. It utilizes GPS along with Bluetooth Low Energy (BLE) to dependably verify user information. In addition, to enhance privacy protection, CoAvoid applies fuzzification and obfuscation measures to shelter sensitive data, making both servers and users agnostic to information of both low and high-risk populations. The evaluation demonstrates good efficacy and security of CoAvoid. Compared with four state-of-art contact tracing applications, CoAvoid can reduce upload data by at least 90% and simultaneously resist wormhole and replay attacks in various scenarios.