  In the current COVID-19 pandemic, manual contact tracing has been proven very
helpful to reach close contacts of infected users and slow down virus
spreading. To improve its scalability, a number of automated contact tracing
(ACT) solutions have proposed and some of them have been deployed. Despite the
dedicated efforts, security and privacy issues of these solutions are still
open and under intensive debate. In this paper, we examine the ACT concept from
a broader perspective, by focusing on not only security and privacy issues but
also functional issues such as interface, usability and coverage. We first
elaborate on these issues and particularly point out the inevitable privacy
leakages in existing BLE-based ACT solutions. Then, we propose a venue-based
ACT concept, which only monitors users' contacting history in
virus-spreading-prone venues and is able to incorporate different location
tracking technologies such as BLE and WIFI. Finally, we instantiate the
venue-based ACT concept and show that our instantiation can mitigate most of
the issues we have identified in our analysis.
