Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Privacy-Protecting COVID-19 Exposure Notification Based on Cluster
  Events   We provide a rough sketch of a simple system design for exposure notification
of COVID-19 infections based on copresence at cluster events -- locations and
times where a threshold number of tested-positive (TP) individuals were
present. Unlike other designs, such as DP3T or the Apple-Google
exposure-notification system, this design does not track or notify based on
detecting direct proximity to TP individuals.
  The design makes use of existing or in-development tests for COVID-19 that
are relatively cheap and return results in less than an hour, and that have
high specificity but may have lower sensitivity. It also uses readily available
location tracking for mobile phones and similar devices. It reports events at
which TP individuals were present but does not link events with individuals or
with other events in an individual's history. Participating individuals are
notified of detected cluster events. They can then compare these locally to
their own location history. Detected cluster events can be publicized through
public channels. Thus, individuals not participating in the reporting system
can still be notified of exposure.
  A proper security analysis is beyond the scope of this design sketch. We do,
however, discuss resistance to various adversaries and attacks on privacy as
well as false-reporting attacks.

15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph