Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: COVID-19 Contact-tracing Apps: a Survey on the Global Deployment and
  Challenges   To address the massive spike in uncertainties triggered by the coronavirus
disease (COVID-19), there is an ever-increasing number of national governments
that are rolling out contact-tracing Apps to aid the containment of the virus.
The first hugely contentious issue facing the Apps is the deployment framework,
i.e. centralized or decentralized. Based on this, the debate branches out to
the corresponding technologies that underpin these architectures, i.e. GPS, QR
codes, and Bluetooth. This work conducts a pioneering review of the above
scenarios and contributes a geolocation mapping of the current deployment. The
Apps vulnerabilities and the directions of research are identified, with a
special focus on the Bluetooth-inspired decentralized paradigm.

8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex