Security enhanced Emergency Situation Detection System for Ambient Assisted Living

Typical wearable devices use a dedicated mobile phone as relay node to transfer the collected sensor data to a server. However, such relay nodes can be faulty or inactive due to various reasons, leading to interruptions of the communication link. To mitigate this challenge, we propose a novel security-enhanced emergency situation detection system, where 3\textsuperscript{rd} party unknown mobile relays are used instead of dedicated gateways as opposed to many existing solutions for IoT healthcare applications. The proposed underlying key agreement and authentication scheme ensures anonymity and untraceability for both sensors (wearable devices) and relay nodes, and relies on symmetric key-based operations to function under resource-constrained environments. We have also developed a prototype of the system using commercial off-the-shelf devices to verify the proposed method's validity and evaluate the performance advantage over existing approaches. Bluetooth Low Energy (BLE) communication technology is used to connect sensor nodes (wearable devices) and mobile relays. After sending medical data to the cloud server, the relay node is responsible for emergency detection and alert generation.