ABSTRACT
Advancements in mobile computing and embedded system technologies show superiority in controlling the transmission of a virus during the COVID-19 pandemic. They provide rapid contact data compared to manual contact tracing and medical monitoring methodologies. Data tracing capabilities were achieved by existing technologies via the utilization of smartphone-based exposure notifications systems and proximity sensing tools based on Bluetooth/GPS. Such systems lack user privacy and data anonymization capabilities, it also requires that users have continuous access to smartphones. This paper proposes the development of a lightweight wearable prototype for contact tracing. The proposed system is based on the deployment of an IoT development board, incorporated with a Bluetooth chipset for proximity sensing. To overcome the problem of user-to-smartphone accessibility, the processing of contact data by the exposure notification system has been migrated from mobile computing to a contact tracer management server that is managed by the community. Daily contact exposures to the virus are recorded by each user's contact tracing system and stored in the user's blockchain. Data integrity and immunity against data injection attacks were achieved via the implementation of lightweight block chaining and validation schemes. Data anonymization was also supported via the utilization of the onboard AES crypto engine. Meanwhile, support for user anonymity was incorporated into the proposed system through the implementation of an anonymous authentication protocol based on the Zero-Knowledge Proof (ZKP) approach. Finally, we have analyzed the performance of the system in terms of power consumption under various systems settings, such as encryption key size and the required number of ZKP validation attempts per authentication session.