<s>
Proton	B-Application
VPN	I-Application
is	O
a	O
VPN	B-Application
service	I-Application
operated	O
by	O
the	O
Swiss	O
company	O
Proton	O
AG	O
,	O
the	O
company	O
behind	O
the	O
email	O
service	O
Proton	B-Application
Mail	I-Application
.	O
</s>
<s>
According	O
to	O
its	O
official	O
website	O
,	O
Proton	B-Application
VPN	I-Application
and	O
Proton	B-Application
Mail	I-Application
share	O
the	O
same	O
management	O
team	O
,	O
offices	O
,	O
and	O
technical	O
resources	O
,	O
and	O
are	O
operated	O
from	O
Proton	O
's	O
headquarters	O
in	O
Geneva	O
,	O
Switzerland	B-Protocol
.	O
</s>
<s>
As	O
of	O
4	O
January	O
2023	O
,	O
Proton	B-Application
VPN	I-Application
has	O
a	O
total	O
of	O
1,904	O
servers	B-Application
,	O
sited	O
in	O
67	O
different	O
nations	O
.	O
</s>
<s>
Although	O
ProtonVPN	B-Application
owns	O
and	O
operates	O
a	O
portion	O
of	O
their	O
servers	B-Application
,	O
the	O
bulk	O
majority	O
are	O
owned	O
and	O
operated	O
by	O
ASNs	O
such	O
as	O
M247	O
and	O
Datacamp	O
Limited	O
.	O
</s>
<s>
Its	O
service	O
is	O
available	O
for	O
Windows	B-Application
,	O
MacOS	B-Application
,	O
Linux	B-Application
,	O
Android	B-Application
,	O
and	O
iOS	B-Application
,	O
and	O
also	O
has	O
a	O
command-line	B-Application
tool	I-Application
for	O
Linux	B-Application
and	O
can	O
be	O
implemented	O
using	O
the	O
IPSEC	B-Protocol
protocol	O
.	O
</s>
<s>
Proton	B-Application
VPN	I-Application
can	O
also	O
be	O
installed	O
on	O
a	O
Wireless	B-Device
Router	I-Device
.	O
</s>
<s>
Proton	B-Application
VPN	I-Application
utilizes	O
OpenVPN	B-Language
(	O
UDP/TCP	O
)	O
and	O
the	O
IKEv2	B-Protocol
protocol	O
,	O
with	O
AES-256	B-Algorithm
encryption	O
.	O
</s>
<s>
In	O
January	O
2020	O
,	O
Proton	B-Application
VPN	I-Application
released	O
its	O
source	O
code	O
on	O
all	O
platforms	O
and	O
had	O
SEC	O
Consult	O
conduct	O
an	O
independent	O
security	O
audit	O
.	O
</s>
<s>
In	O
July	O
2021	O
,	O
Proton	B-Application
VPN	I-Application
added	O
WireGuard	B-Application
protocol	O
as	O
beta	O
version	O
.	O
</s>
<s>
In	O
a	O
September	O
2019	O
review	O
by	O
TechRadar	O
,	O
Proton	B-Application
VPN	I-Application
received	O
4	O
1/2	O
out	O
of	O
5	O
stars	O
.	O
</s>
<s>
A	O
February	O
2019	O
PC	O
Magazine	O
UK	O
review	O
rated	O
Proton	B-Application
VPN	I-Application
at	O
4	O
1/2	O
out	O
of	O
5	O
based	O
on	O
its	O
services	O
and	O
price	O
range	O
.	O
</s>
