Coronavirus Contact Tracing using Bluetooth Low Energy and Smartphones

接触者追踪对于防止传染病的进一步传播至关重要。通常，这样的任务是通过少数授权人员手动执行的。然而，信息到达很可能与感染者有密切接触的人手中需要时间。由于迫切需要一种有效的接触追踪方法，在本项目中，我们将利用智能手机上的蓝牙低能量(BLE)信号来开发一种新型的智能接触追踪(SCT)系统。通过智能手机应用程序，系统将根据他们与人的距离和互动的持续时间将直接接触者分为高风险和低风险。此外，引入的SCT将使用邻近信息在违反建议的物理距离时触发实时警报。建议的接触者追踪方法是安全地设计的，以防止可能的信息泄露。当用户在公共场所时，我们利用BLE的信标功能来广播加密的分组。由于信标分组是通过不可连接的广告通道传输的，因此附近的设备无法故意访问智能手机。此外，利用唯一且不可能被任何设备在其他情况下复制的签名信息对分组进行加密。

Contact tracing is of critical importance in preventing the further spread of infectious disease. Usually, such a task is performed manually through a few authorized personnel. However, it takes time for the information to reach the people who are very likely to be in close contact with the infected patient. Motivated by the urgent need for an effective contact tracing method, in this project we will develop a novel Smart Contact Tracing (SCT) system by exploiting the Bluetooth Low Energy (BLE) signals on the smartphone. Through a smartphone application, the system will classify the immediate contacts into high risk and low risk, according to their proximity from a person and the duration of the interaction. Additionally, the introduced SCT will use the proximity information to trigger a real-time alert when the recommended physical distancing is violated. The proposed contact tracing method is securely designed to prevent possible information leaks. We leverage the beaconing feature of BLE to broadcast an encrypted packet when the user is in the public space. Since the beaconing packet is transmitted through non-connectable advertising channels, no nearby devices can access the smartphone intentionally. Furthermore, the packet is encrypted with a piece of signature information that is unique and impossible to be duplicated by any device on other occasions.