<s>
The	O
(	O
Google/Apple	O
)	O
Exposure	B-Application
Notification	I-Application
(	O
GAEN	B-Application
)	O
system	O
,	O
originally	O
known	O
as	O
the	O
Privacy-Preserving	O
Contact	O
Tracing	O
Project	O
,	O
is	O
a	O
framework	O
and	O
protocol	O
specification	O
developed	O
by	O
Apple	O
Inc	O
.	O
and	O
Google	B-Application
to	O
facilitate	O
digital	B-Protocol
contact	I-Protocol
tracing	I-Protocol
during	O
the	O
COVID-19	O
pandemic	O
.	O
</s>
<s>
When	O
used	O
by	O
health	O
authorities	O
,	O
it	O
augments	O
more	O
traditional	O
contact	O
tracing	O
techniques	O
by	O
automatically	O
logging	O
encounters	O
with	O
other	O
notification	O
system	O
users	O
using	O
their	O
Android	B-Application
or	O
iOS	B-Application
smartphone	B-Application
.	O
</s>
<s>
Exposure	B-Application
Notification	I-Application
is	O
a	O
decentralized	O
reporting	O
based	O
protocol	O
built	O
on	O
a	O
combination	O
of	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
technology	O
and	O
privacy-preserving	O
cryptography	O
.	O
</s>
<s>
It	O
is	O
used	O
as	O
an	O
opt-in	O
feature	O
within	O
COVID-19	B-Application
apps	I-Application
developed	O
and	O
published	O
by	O
authorized	O
health	O
authorities	O
.	O
</s>
<s>
Originally	O
unveiled	O
on	O
April	O
10	O
,	O
2020	O
,	O
it	O
was	O
first	O
made	O
available	O
on	O
iOS	B-Application
on	O
May	O
20	O
,	O
2020	O
as	O
part	O
of	O
the	O
iOS	B-Operating_System
13.5	I-Operating_System
update	O
and	O
on	O
December	O
14	O
,	O
2020	O
as	O
part	O
of	O
the	O
iOS	B-Operating_System
12.5	I-Operating_System
update	O
for	O
older	O
iPhones	B-Operating_System
.	O
</s>
<s>
On	O
Android	B-Application
,	O
it	O
was	O
added	O
to	O
devices	O
via	O
a	O
Google	B-Application
Play	I-Application
Services	I-Application
update	O
,	O
supporting	O
all	O
versions	O
since	O
Android	B-Application
Marshmallow	I-Application
.	O
</s>
<s>
The	O
Apple/Google	O
protocol	O
is	O
similar	O
to	O
the	O
Decentralized	B-Protocol
Privacy-Preserving	I-Protocol
Proximity	I-Protocol
Tracing	I-Protocol
(	O
DP-3T	B-Protocol
)	O
protocol	O
created	O
by	O
the	O
European	O
DP-3T	B-Protocol
consortium	O
and	O
the	O
Temporary	B-Protocol
Contact	I-Protocol
Number	I-Protocol
(	O
TCN	O
)	O
protocol	O
by	O
Covid	B-Application
Watch	I-Application
,	O
but	O
is	O
implemented	O
at	O
the	O
operating	B-General_Concept
system	I-General_Concept
level	O
,	O
which	O
allows	O
for	O
more	O
efficient	O
operation	O
as	O
a	O
background	O
process	B-Operating_System
.	O
</s>
<s>
Since	O
May	O
2020	O
,	O
a	O
variant	O
of	O
the	O
DP-3T	B-Protocol
protocol	O
is	O
supported	O
by	O
the	O
Exposure	B-Application
Notification	I-Application
Interface	O
.	O
</s>
<s>
Other	O
protocols	O
are	O
constrained	O
in	O
how	O
they	O
operate	O
as	O
they	O
have	O
no	O
special	O
privilege	O
over	O
normal	O
apps	B-Application
.	O
</s>
<s>
This	O
leads	O
to	O
issues	O
,	O
particularly	O
on	O
iOS	B-Application
devices	O
where	O
digital	B-Protocol
contact	I-Protocol
tracing	I-Protocol
apps	B-Application
running	O
in	O
the	O
background	O
experience	O
significantly	O
degraded	O
performance	O
.	O
</s>
<s>
The	O
joint	O
approach	O
is	O
also	O
designed	O
to	O
maintain	O
interoperability	O
between	O
Android	B-Application
and	O
iOS	B-Application
devices	O
,	O
which	O
constitute	O
the	O
sheer	O
majority	O
of	O
the	O
market	O
.	O
</s>
<s>
In	O
late	O
April	O
,	O
Google	B-Application
and	O
Apple	O
shifted	O
the	O
emphasis	O
of	O
the	O
naming	O
of	O
the	O
system	O
,	O
describing	O
it	O
as	O
an	O
"	O
exposure	B-Application
notification	I-Application
service	O
"	O
,	O
rather	O
than	O
"	O
contact	O
tracing	O
"	O
system	O
.	O
</s>
<s>
Typically	O
digital	B-Protocol
contact	I-Protocol
tracing	I-Protocol
protocols	O
have	O
two	O
major	O
responsibilities	O
:	O
encounter	B-Application
logging	I-Application
and	O
infection	O
reporting	O
.	O
</s>
<s>
Exposure	B-Application
Notification	I-Application
only	O
defines	O
encounter	B-Application
logging	I-Application
which	O
is	O
a	O
decentralized	O
architecture	O
,	O
with	O
the	O
majority	O
of	O
the	O
infection	O
reporting	O
,	O
currently	O
it	O
is	O
centralized	O
,	O
being	O
delegated	O
to	O
individual	O
app	O
implementations	O
.	O
</s>
<s>
To	O
handle	O
encounter	B-Application
logging	I-Application
,	O
the	O
system	O
uses	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
to	O
send	O
tracking	O
messages	O
to	O
nearby	O
devices	O
running	O
the	O
protocol	O
to	O
discover	O
encounters	O
with	O
other	O
people	O
.	O
</s>
<s>
The	O
Google-developed	O
reference	O
implementation	O
calls	O
for	O
a	O
health	O
official	O
to	O
request	O
a	O
one-time	O
verification	O
code	O
(	O
VC	O
)	O
from	O
a	O
verification	O
server	O
,	O
which	O
the	O
user	O
enters	O
into	O
the	O
encounter	B-Application
logging	I-Application
app	O
.	O
</s>
<s>
Google	B-Application
and	O
Apple	O
intend	O
to	O
use	O
the	O
received	O
signal	O
strength	O
(	O
RSSI	O
)	O
of	O
the	O
beacon	O
messages	O
as	O
a	O
source	O
to	O
infer	O
proximity	O
.	O
</s>
<s>
From	O
this	O
a	O
16	O
byte	O
Daily	O
Tracing	O
Key	O
is	O
derived	O
using	O
the	O
algorithm	O
,	O
where	O
is	O
a	O
HKDF	B-Algorithm
function	O
using	O
SHA-256	O
,	O
and	O
is	O
the	O
day	O
number	O
for	O
the	O
24-hour	O
window	O
the	O
broadcast	O
is	O
in	O
starting	O
from	O
Unix	O
Epoch	O
Time	O
.	O
</s>
<s>
From	O
the	O
daily	O
tracing	O
key	O
a	O
16-byte	O
temporary	O
Rolling	O
Proximity	O
Identifier	O
is	O
generated	O
every	O
10	O
minutes	O
with	O
the	O
algorithm	O
,	O
where	O
is	O
a	O
HMAC	B-Algorithm
function	O
using	O
SHA-256	O
,	O
and	O
is	O
the	O
time	O
interval	O
number	O
,	O
representing	O
a	O
unique	O
index	O
for	O
every	O
10	O
minute	O
period	O
in	O
a	O
24-hour	O
day	O
.	O
</s>
<s>
The	O
Truncate	O
function	O
returns	O
the	O
first	O
16	O
bytes	O
of	O
the	O
HMAC	B-Algorithm
value	O
.	O
</s>
<s>
The	O
following	O
algorithm	O
is	O
used	O
:	O
,	O
where	O
is	O
an	O
AES	B-Algorithm
cryptography	O
function	O
with	O
a	O
128-bit	O
key	O
,	O
the	O
data	O
is	O
one	O
16-byte	O
block	O
,	O
denotes	O
the	O
Unix	O
Epoch	O
Time	O
at	O
the	O
moment	O
the	O
roll	O
occurs	O
,	O
and	O
is	O
the	O
corresponding	O
10-minute	O
interval	O
number	O
.	O
</s>
<s>
The	O
following	O
algorithm	O
is	O
used	O
:	O
,	O
where	O
denotes	O
AES	B-Algorithm
encryption	I-Algorithm
with	O
a	O
128-bit	O
key	O
in	O
CTR	O
mode	O
.	O
</s>
<s>
Apps	B-Application
implementing	O
Exposure	B-Application
Notification	I-Application
are	O
only	O
allowed	O
to	O
collect	O
personal	O
information	O
from	O
users	O
on	O
a	O
voluntary	O
basis	O
.	O
</s>
<s>
Consent	O
must	O
be	O
obtained	O
by	O
the	O
user	O
to	O
enable	O
the	O
system	O
or	O
publicize	O
a	O
positive	O
result	O
through	O
the	O
system	O
,	O
and	O
apps	B-Application
using	O
the	O
system	O
are	O
prohibited	O
from	O
collecting	O
location	O
data	O
.	O
</s>
<s>
On	O
April	O
16	O
,	O
the	O
European	O
Union	O
started	O
the	O
process	B-Operating_System
of	O
assessing	O
the	O
proposed	O
system	O
for	O
compatibility	O
with	O
privacy	O
and	O
data	O
protection	O
laws	O
,	O
including	O
the	O
General	O
Data	O
Protection	O
Regulation	O
(	O
GDPR	O
)	O
.	O
</s>
<s>
On	O
April	O
17	O
,	O
2020	O
,	O
the	O
UK	O
's	O
Information	O
Commissioner	O
's	O
Office	O
,	O
a	O
supervisory	O
authority	O
for	O
data	O
protection	O
,	O
published	O
an	O
opinion	O
analyzing	O
both	O
Exposure	B-Application
Notification	I-Application
and	O
the	O
Decentralized	B-Protocol
Privacy-Preserving	I-Protocol
Proximity	I-Protocol
Tracing	I-Protocol
protocol	I-Protocol
,	O
stating	O
that	O
the	O
systems	O
are	O
"	O
aligned	O
with	O
the	O
principles	O
of	O
data	O
protection	O
by	O
design	O
and	O
by	O
default	O
"	O
(	O
as	O
mandated	O
by	O
the	O
GDPR	O
)	O
.	O
</s>
<s>
Exposure	B-Application
Notification	I-Application
is	O
compatible	O
with	O
Android	B-Application
devices	O
supporting	O
Bluetooth	B-General_Concept
Low	I-General_Concept
Energy	I-General_Concept
and	O
running	O
Android	B-Application
6.0	I-Application
"	I-Application
Marshmallow	I-Application
"	I-Application
and	O
newer	O
with	O
Google	B-Application
Mobile	I-Application
Services	I-Application
.	O
</s>
<s>
It	O
is	O
serviced	O
via	O
updates	O
to	O
Google	B-Application
Play	I-Application
Services	I-Application
,	O
ensuring	O
compatibility	O
with	O
the	O
majority	O
of	O
Android	B-Application
devices	O
released	O
outside	O
of	O
Mainland	O
China	O
,	O
and	O
not	O
requiring	O
it	O
to	O
be	O
integrated	O
into	O
Android	B-Application
firmware	O
updates	O
(	O
which	O
would	O
hinder	O
deployment	O
by	O
relying	O
on	O
individual	O
OEMs	O
)	O
.	O
</s>
<s>
On	O
iOS	B-Application
,	O
EN	O
is	O
serviced	O
via	O
operating	B-General_Concept
system	I-General_Concept
updates	O
.	O
</s>
<s>
It	O
was	O
first	O
introduced	O
as	O
part	O
of	O
iOS	B-Operating_System
13.5	I-Operating_System
on	O
May	O
20	O
,	O
2020	O
.	O
</s>
<s>
In	O
December	O
2020	O
,	O
Apple	O
released	O
iOS	B-Operating_System
12.5	I-Operating_System
,	O
which	O
backported	O
EN	O
support	O
to	O
iPhone	B-Operating_System
models	O
that	O
cannot	O
be	O
upgraded	O
to	O
iOS	B-Operating_System
13	I-Operating_System
,	O
including	O
iPhone	B-Operating_System
6	I-Operating_System
and	O
older	O
.	O
</s>
<s>
Exposure	B-Application
Notification	I-Application
apps	B-Application
may	O
only	O
be	O
released	O
by	O
public	O
health	O
authorities	O
.	O
</s>
<s>
To	O
discourage	O
fragmentation	O
,	O
each	O
country	O
will	O
typically	O
be	O
restricted	O
to	O
one	O
app	O
,	O
although	O
Apple	O
and	O
Google	B-Application
stated	O
that	O
they	O
would	O
accommodate	O
regionalized	O
approaches	O
if	O
a	O
country	O
elects	O
to	O
do	O
so	O
.	O
</s>
<s>
Apple	O
and	O
Google	B-Application
released	O
reference	O
implementations	O
for	O
apps	B-Application
utilizing	O
the	O
system	O
,	O
which	O
can	O
be	O
used	O
as	O
a	O
base	O
.	O
</s>
<s>
On	O
September	O
1	O
,	O
2020	O
,	O
the	O
consortium	O
announced	O
"	O
Exposure	B-Application
Notifications	I-Application
Express	O
"	O
(	O
EN	O
Express	O
)	O
,	O
a	O
system	O
designed	O
to	O
ease	O
adoption	O
of	O
the	O
protocol	O
by	O
health	O
authorities	O
by	O
removing	O
the	O
need	O
to	O
develop	O
an	O
app	O
themselves	O
.	O
</s>
<s>
On	O
Android	B-Application
,	O
this	O
data	O
is	O
used	O
to	O
generate	O
an	O
app	O
,	O
and	O
a	O
configuration	O
profile	O
that	O
can	O
also	O
be	O
deployed	O
to	O
users	O
via	O
Google	B-Application
Play	I-Application
Services	I-Application
without	O
a	O
dedicated	O
app	O
.	O
</s>
<s>
On	O
iOS	B-Application
,	O
the	O
functionality	O
is	O
integrated	O
directly	O
at	O
the	O
system	O
level	O
on	O
iOS	B-Operating_System
13.7	I-Operating_System
and	O
newer	O
without	O
a	O
dedicated	O
app	O
.	O
</s>
<s>
On	O
December	O
14	O
,	O
2020	O
,	O
Apple	O
released	O
iOS	B-Operating_System
12.5	I-Operating_System
,	O
bringing	O
support	O
for	O
Exposure	B-Application
Notifications	I-Application
to	O
older	O
iPhones	B-Operating_System
.	O
</s>
<s>
The	O
last	O
information	O
update	O
on	O
the	O
“	O
Exposure	B-Application
Notification	I-Application
Systems	O
”	O
partnership	O
was	O
a	O
year	O
end	O
review	O
issued	O
by	O
Google	B-Application
in	O
December	O
2020	O
:	O
"	O
we	O
plan	O
to	O
keep	O
you	O
updated	O
here	O
with	O
new	O
information	O
again	O
next	O
year	O
"	O
.	O
</s>
<s>
Nothing	O
has	O
however	O
been	O
issued	O
on	O
the	O
one	O
year	O
anniversary	O
of	O
the	O
launch	O
of	O
the	O
“	O
Exposure	B-Application
Notification	I-Application
Interface	O
”	O
API	O
in	O
spite	O
of	O
important	O
changes	O
on	O
the	O
pandemic	O
front	O
such	O
as	O
vaccination	O
,	O
variants	O
,	O
digital	O
health	O
passports	O
,	O
app	O
adoption	O
challenges	O
as	O
well	O
as	O
growing	O
interest	O
for	O
tracking	O
QR	O
codes	O
(	O
and	O
notifying	O
from	O
that	O
basis	O
)	O
on	O
a	O
mostly	O
airborne	O
transmitted	O
virus	O
.	O
</s>
<s>
Basic	O
support	O
remains	O
provided	O
through	O
the	O
apps	B-Application
store	O
released	O
by	O
authorized	O
public	O
health	O
agencies	O
,	O
including	O
enforcement	O
of	O
the	O
personal	O
privacy	O
protection	O
framework	O
as	O
demonstrated	O
on	O
the	O
UK	O
NHS	O
challenge	O
in	O
support	O
of	O
their	O
contact	O
tracers	O
.	O
</s>
<s>
In	O
June	O
2021	O
,	O
Google	B-Application
faced	O
allegations	O
that	O
it	O
had	O
automatically	O
downloaded	O
Massachusetts	O
 '	O
"	O
MassNotify	O
"	O
app	O
to	O
Android	B-Application
devices	O
without	O
user	O
consent	O
.	O
</s>
<s>
Google	B-Application
clarified	O
that	O
it	O
had	O
not	O
actually	O
downloaded	O
the	O
app	O
to	O
user	O
devices	O
,	O
and	O
that	O
Google	B-Application
Play	I-Application
Services	I-Application
was	O
being	O
used	O
to	O
deploy	O
an	O
EN	O
Express	O
configuration	O
profile	O
that	O
would	O
allow	O
it	O
to	O
be	O
enabled	O
via	O
the	B-Application
Google	I-Application
Settings	O
app	O
without	O
needing	O
to	O
download	O
a	O
separate	O
app	O
.	O
</s>
<s>
On	O
April	O
26	O
,	O
after	O
initially	O
backing	O
PEPP-PT	B-Protocol
,	O
Germany	O
announced	O
it	O
would	O
back	O
Exposure	B-Application
Notification	I-Application
,	O
followed	O
shortly	O
after	O
by	O
Ireland	O
and	O
Italy	O
.	O
</s>
<s>
Despite	O
already	O
adopting	O
the	O
centralised	O
BlueTrace	B-Protocol
protocol	O
,	O
Australia	O
's	O
Department	O
of	O
Health	O
and	O
Digital	O
Transformation	O
Agency	O
were	O
investigating	O
whether	O
the	O
protocol	O
could	O
be	O
implemented	O
to	O
overcome	O
limitations	O
of	O
its	O
COVIDSafe	B-Application
app	O
.	O
</s>
<s>
On	O
May	O
25	O
,	O
Switzerland	O
became	O
the	O
first	O
country	O
to	O
launch	O
an	O
app	O
leveraging	O
the	O
protocol	O
,	O
SwissCovid	B-Application
,	O
beginning	O
with	O
a	O
small	O
pilot	O
group	O
.	O
</s>
<s>
In	O
England	O
,	O
the	O
National	O
Health	O
Service	O
(	O
NHS	O
)	O
trialed	O
both	O
an	O
in-house	B-Application
app	I-Application
on	O
a	O
centralized	O
platform	O
developed	O
by	O
its	O
NHSX	O
division	O
,	O
and	O
a	O
second	O
app	O
using	O
Exposure	B-Application
Notification	I-Application
.	O
</s>
<s>
On	O
June	O
18	O
,	O
the	O
NHS	O
announced	O
that	O
it	O
would	O
focus	O
on	O
using	O
Exposure	B-Application
Notification	I-Application
to	O
complement	O
manual	O
contact	O
tracing	O
,	O
citing	O
tests	O
on	O
the	O
Isle	O
of	O
Wight	O
showing	O
that	O
it	O
had	O
better	O
cross-device	O
compatibility	O
(	O
and	O
would	O
also	O
be	O
compatible	O
with	O
other	O
European	O
approaches	O
)	O
,	O
but	O
that	O
its	O
distance	O
calculations	O
were	O
not	O
as	O
reliable	O
as	O
the	O
centralized	O
version	O
of	O
the	O
app	O
,	O
an	O
issue	O
which	O
was	O
later	O
rectified	O
.	O
</s>
<s>
A	O
study	O
of	O
the	O
impact	O
of	O
Exposure	B-Application
Notification	I-Application
in	O
England	O
and	O
Wales	O
estimated	O
that	O
it	O
averted	O
8,700	O
(	O
95%	O
confidence	O
interval	O
4,700	O
–	O
13,500	O
)	O
deaths	O
out	O
of	O
the	O
32,500	O
recorded	O
from	O
its	O
introduction	O
on	O
24	O
September	O
2020	O
to	O
31	O
December	O
2020	O
.	O
</s>
<s>
Canada	O
launched	O
its	O
COVID	B-Application
Alert	I-Application
app	O
,	O
co-developed	O
in	O
partnership	O
with	O
BlackBerry	O
Limited	O
and	O
Shopify	O
,	O
on	O
July	O
31	O
in	O
Ontario	O
.	O
</s>
<s>
In	O
May	O
2020	O
,	O
Covid	B-Application
Watch	I-Application
launched	O
the	O
first	O
calibration	O
and	O
beta	O
testing	O
pilot	O
of	O
the	O
GAEN	B-Application
APIs	O
in	O
the	O
United	O
States	O
at	O
the	O
University	O
of	O
Arizona	O
.	O
</s>
<s>
The	O
U.S.	O
Association	O
of	O
Public	O
Health	O
Laboratories	O
(	O
APHL	O
)	O
stated	O
in	O
July	O
2020	O
that	O
it	O
was	O
working	O
with	O
Apple	O
,	O
Google	B-Application
,	O
and	O
Microsoft	O
on	O
a	O
national	O
reporting	O
server	O
for	O
use	O
with	O
the	O
protocol	O
,	O
which	O
it	O
stated	O
would	O
ease	O
adoption	O
and	O
interoperability	O
between	O
states	O
.	O
</s>
<s>
In	O
August	O
2020	O
,	O
Google	B-Application
stated	O
that	O
at	O
least	O
20	O
U.S.	O
states	O
had	O
expressed	O
interest	O
in	O
using	O
the	O
protocol	O
.	O
</s>
<s>
In	O
Alabama	B-Application
,	O
the	O
Alabama	B-Application
Department	O
of	O
Public	O
Health	O
,	O
University	O
of	O
Alabama	B-Application
at	O
Birmingham	O
,	O
and	O
the	O
University	O
of	O
Alabama	B-Application
System	O
deployed	O
the	O
"	O
GuideSafe	O
"	O
app	O
for	O
university	O
students	O
returning	O
to	O
campus	O
,	O
which	O
includes	O
Exposure	B-Application
Notification	I-Application
features	O
.	O
</s>
<s>
On	O
August	O
5	O
,	O
the	O
Virginia	B-Application
Department	O
of	O
Health	O
released	O
its	O
"	O
COVIDWise	O
"	O
app	O
—	O
making	O
it	O
the	O
first	O
U.S.	O
state	O
to	O
release	O
an	O
Exposure	O
Notification-based	O
app	O
for	O
the	O
general	O
public	O
.	O
</s>
<s>
Maryland	O
,	O
Nevada	O
,	O
Virginia	B-Application
,	O
and	O
Washington	O
,	O
D.C.	O
have	O
announced	O
plans	O
to	O
use	O
EN	O
Express	O
.	O
</s>
<s>
In	O
September	O
,	O
Delaware	O
,	O
New	O
Jersey	O
,	O
New	O
York	O
,	O
and	O
Pennsylvania	O
all	O
adopted	O
"	O
COVID	B-Application
Alert	I-Application
"	O
apps	B-Application
developed	O
by	O
NearForm	O
,	O
which	O
are	O
based	O
on	O
its	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
app	O
.	O
</s>
<s>
In	O
Nov	O
2020	O
,	O
Bermuda	O
launched	O
the	O
Wehealth	O
Bermuda	O
app	O
developed	O
by	O
Wehealth	O
,	O
a	O
Public	O
Benefit	O
Corporation	O
,	O
which	O
was	O
based	O
on	O
the	O
Covid	B-Application
Watch	I-Application
app	O
released	O
in	O
Arizona	O
.	O
</s>
<s>
Alberta	O
and	O
British	O
Columbia	O
have	O
declined	O
its	O
use.eRouška	O
(	O
eMask	O
)	O
September	O
17	O
,	O
2020Since	O
version	O
2.1SmittestopJune	O
18	O
,	O
2020HoiaAugust	O
20	O
,	O
2020KoronavilkkuAugust	O
31	O
,	O
2020Corona-Warn-AppJune	O
16	O
,	O
2020BEAT	O
Covid	O
GibraltarJune	O
18	O
,	O
2020Based	O
on	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
and	O
will	O
interoperate	O
with	O
it.Rakning	O
C-19May	O
12	O
,	O
2021GEAN	O
implementation	O
activated	O
in	O
May	O
2021	O
,	O
replaced	O
previous	O
version	O
of	O
app	O
which	O
used	O
GPS	O
tracking	O
stored	O
on-device	O
launched	O
in	O
April	O
2020.COVID	O
Tracker	O
IrelandJuly	O
7	O
,	O
2020ImmuniJune	O
1	O
,	O
2020COCOAJune	O
19	O
,	O
2020Jersey	O
COVID	O
AlertSeptember	O
21	O
,	O
2020Apturi	O
CovidMay	O
29	O
,	O
2020Ma3anJuly	O
16	O
,	O
2020	O
NetherlandsCoronaMelderOctober	O
10	O
,	O
2020	O
(	O
full	O
release	O
)	O
New	O
ZealandNZ	O
COVID	O
TracerDecember	O
10	O
,	O
2020	O
(	O
full	O
release	O
)	O
SmittestoppDecember	O
21	O
,	O
2020Replaced	O
a	O
version	O
of	O
the	O
app	O
that	O
was	O
suspended	O
earlier	O
in	O
the	O
year	O
due	O
to	O
scrutiny	O
from	O
the	O
local	O
Norwegian	O
Data	O
Protection	O
Authority.StaySafe.phMarch	O
29	O
,	O
2021GAEN	O
implementation	O
activated	O
in	O
April	O
2021	O
ProteGO	O
SafeJune	O
9	O
,	O
2020Update	O
to	O
existing	O
encounter	B-Application
logging	I-Application
app.STAYAWAY	O
COVIDAugust	O
28	O
,	O
2020Gosuslugi	O
.	O
</s>
<s>
Covid	O
TrackerNovember	O
23	O
,	O
2020https://play.google.com/store/apps/details	O
?	O
id	O
=	O
com.minsvyaz.gosuslugi.exposurenotificationdroidCOVID	O
Alert	O
SASeptember	O
1	O
,	O
2020Radar	O
COVIDJune	O
30	O
,	O
2020	O
(	O
beta	O
test	O
)	O
SwissCovidMay	O
26	O
,	O
2020	O
(	O
pilot	O
phase	O
)	O
臺灣社交距離May	O
3	O
,	O
2021Thai	O
Covid	O
AlertApril	O
26	O
,	O
2022NHS	O
COVID-19September	O
24	O
,	O
2020StopCOVID	O
NIJuly	O
30	O
,	O
2020Interoperates	O
with	O
COVID	O
Tracker	O
Ireland.link	O
=	O
Scotland|alt	O
=	O
Scotland|23x23px	O
ScotlandProtect	O
ScotlandSeptember	O
11	O
,	O
2020Based	O
on	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
and	O
will	O
interoperate	O
with	O
it	O
.	O
</s>
<s>
United	O
States	O
AlabamaGuideSafeAugust	O
3	O
,	O
2020Targeting	O
University	O
of	O
Alabama	B-Application
students	O
as	O
part	O
of	O
a	O
larger	O
program	O
under	O
the	O
same	O
name	O
.	O
</s>
<s>
CaliforniaCA	O
NotifyDecember	O
10	O
,	O
2020	O
ColoradoCO	O
Exposure	O
NotificationsOctober	O
25	O
,	O
2020	O
ConnecticutCOVID	O
Alert	O
CTNovember	O
12	O
,	O
2020	O
DelawareCOVID	O
Alert	O
DESeptember	O
15	O
,	O
2020Based	O
on	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
.	O
</s>
<s>
GuamGuam	O
Covid	O
AlertSeptember	O
10	O
,	O
2020Based	O
on	O
the	O
PathCheck	O
Foundation	O
's	O
GAEN	B-Application
Mobile	O
project	O
HawaiiAloha	O
Safe	O
AlertNovember	O
11	O
,	O
2020Based	O
on	O
the	O
PathCheck	O
Foundation	O
's	O
GAEN	B-Application
Mobile	O
project	O
LouisianaCOVID	O
DefenseJanuary	O
22	O
,	O
2021Based	O
on	O
the	O
PathCheck	O
Foundation	O
's	O
GAEN	B-Application
Mobile	O
project	O
MarylandMD	O
COVID	O
AlertOctober	O
10	O
,	O
2020MassachusettsMassNotifyUses	O
EN	O
Express	O
.	O
</s>
<s>
New	O
JerseyCOVID	O
Alert	O
NJSeptember	O
30	O
,	O
2020Based	O
on	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
.	O
</s>
<s>
New	O
YorkCOVID	O
Alert	O
NYSeptember	O
30	O
,	O
2020Based	O
on	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
.	O
</s>
<s>
North	O
DakotaCare19	O
AlertAugust	O
13	O
,	O
2020	O
PennsylvaniaCOVID	O
Alert	O
PASeptember	O
24	O
,	O
2020Based	O
on	O
COVID	B-Application
Tracker	I-Application
Ireland	I-Application
.	O
</s>
<s>
Some	O
countries	O
,	O
such	O
as	O
France	O
,	O
have	O
pursued	O
centralized	O
approaches	O
to	O
digital	B-Protocol
contact	I-Protocol
tracing	I-Protocol
,	O
in	O
order	O
to	O
maintain	O
records	O
of	O
personal	O
information	O
that	O
can	O
be	O
used	O
to	O
assist	O
in	O
investigating	O
cases	O
.	O
</s>
<s>
The	O
French	O
government	O
asked	O
Apple	O
in	O
April	O
2020	O
to	O
allow	O
apps	B-Application
to	O
perform	O
Bluetooth	O
operations	O
in	O
the	O
background	O
,	O
which	O
would	O
allow	O
the	O
government	O
to	O
create	O
its	O
own	O
system	O
independent	O
of	O
Exposure	B-Application
Notification	I-Application
.	O
</s>
<s>
On	O
August	O
9	O
,	O
the	O
Canadian	O
province	O
of	O
Alberta	O
announced	O
plans	O
to	O
migrate	O
to	O
the	O
EN-based	O
COVID	B-Application
Alert	I-Application
from	O
its	O
BlueTrace-based	O
ABTraceTogether	O
app	O
.	O
</s>
<s>
British	O
Columbia	O
has	O
also	O
declined	O
to	O
adopt	O
COVID	B-Application
Alert	I-Application
,	O
with	O
provincial	O
health	O
officer	O
Bonnie	O
Henry	O
stating	O
that	O
COVID	B-Application
Alert	I-Application
was	O
too	O
"	O
non-specific	O
"	O
.	O
</s>
<s>
Australia	O
's	O
officials	O
have	O
stated	O
its	O
COVIDSafe	B-Application
,	O
which	O
is	O
based	O
on	O
Singapore	O
's	O
BlueTrace	B-Protocol
,	O
will	O
not	O
be	O
shifting	O
from	O
manual	O
intervention	O
.	O
</s>
<s>
Chinese	O
vendor	O
Huawei	O
(	O
which	O
cannot	O
include	O
Google	B-Application
software	O
on	O
its	O
current	O
Android	B-Application
products	O
due	O
to	O
U.S.	O
sanctions	O
)	O
added	O
a	O
OS-level	O
DP-3T	B-Protocol
API	O
known	O
as	O
"	O
Contact	O
Shield	O
"	O
to	O
its	O
Huawei	O
Mobile	O
Services	O
stack	O
in	O
June	O
2020	O
,	O
which	O
the	O
company	O
states	O
is	O
intended	O
to	O
be	O
interoperable	O
with	O
Exposure	B-Application
Notification	I-Application
.	O
</s>
