  Large-scale COVID-19 infections have occurred worldwide, which has caused
tremendous impact on the economy and people's lives. The traditional method for
tracing contagious virus, for example, determining the infection chain
according to the memory of infected people, has many drawbacks. With the
continuous spread of the pandemic, many countries or organizations have started
to study how to use mobile devices to trace COVID-19, aiming to help people
automatically record information about incidents with infected people through
technologies, reducing the manpower required to determine the infection chain
and alerting people at risk of infection. This article gives an overview on
various Bluetooth-based COVID-19 proximity tracing proposals including
centralized and decentralized proposals. We discussed the basic workflow and
the differences between them before providing a survey of five typical
proposals with explanations of their design features and benefits. Then, we
summarized eight security and privacy design goals for Bluetooth-based COVID-19
proximity tracing proposals and applied them to analyze the five proposals.
Finally, open problems and future directions are discussed.
