<s>
Snowflake	B-Application
is	O
a	O
software	O
package	O
for	O
assisting	O
others	O
in	O
circumventing	B-Application
internet	I-Application
censorship	I-Application
by	O
relaying	O
data	O
requests	O
.	O
</s>
<s>
Snowflake	B-Application
relay	O
nodes	O
are	O
meant	O
to	O
be	O
created	O
by	O
people	O
in	O
countries	O
where	O
Tor	B-Application
and	O
Snowflake	B-Application
are	O
not	O
blocked	O
.	O
</s>
<s>
People	O
under	O
censorship	O
then	O
use	O
a	O
Snowflake	B-Application
client	O
,	O
packaged	O
with	O
the	O
Tor	B-Application
Browser	O
or	O
Onion	O
Browser	O
,	O
to	O
access	O
the	O
Tor	B-Application
network	I-Application
,	O
using	O
Snowflake	B-Application
relays	O
as	O
proxy	B-Application
servers	I-Application
.	O
</s>
<s>
Access	O
to	O
the	O
Tor	B-Application
network	I-Application
can	O
in	O
turn	O
give	O
access	O
to	O
other	O
blocked	O
services	O
(	O
like	O
blocked	O
websites	O
)	O
.	O
</s>
<s>
A	O
Snowflake	B-Application
node	O
can	O
be	O
created	O
by	O
either	O
installing	O
a	O
browser	B-Protocol
extension	I-Protocol
,	O
installing	O
a	O
stand-alone	O
program	O
,	O
or	O
browsing	O
a	O
webpage	O
with	O
an	O
embedded	O
Snowflake	B-Application
relay	O
.	O
</s>
<s>
Tor	B-Application
relays	O
content	O
requests	O
through	O
a	O
chain	O
of	O
Tor	B-Application
nodes	I-Application
,	O
including	O
Snowflake	B-Application
nodes	O
(	O
onion	B-Protocol
routing	I-Protocol
)	O
.	O
</s>
<s>
A	O
common	O
countermeasure	O
is	O
blocking	O
Tor	B-Application
nodes	I-Application
;	O
the	O
number	O
and	O
shifting	O
nature	O
of	O
the	O
Snowflake	B-Application
nodes	O
make	O
identifying	O
and	O
blocking	O
connections	O
to	O
these	O
nodes	O
more	O
difficult	O
.	O
</s>
<s>
Tor	B-Application
is	O
itself	O
illegal	O
in	O
some	O
countries	O
.	O
</s>
<s>
Snowflake	B-Application
was	O
originated	O
by	O
Serene	O
,	O
a	O
hacker	O
and	O
former	O
Google	O
engineer	O
and	O
concert	O
pianist	O
.	O
</s>
<s>
The	O
name	O
"	O
Snowflake	B-Application
"	O
was	O
coined	O
as	O
her	O
metaphor	O
for	O
a	O
large	O
number	O
of	O
ephemeral	O
proxies	O
in	O
relation	O
to	O
"	O
ICE	O
Negotiation	O
"	O
.	O
</s>
<s>
In	O
2019	O
,	O
it	O
became	O
available	O
as	O
a	O
browser	B-Protocol
extension	I-Protocol
for	O
Firefox	B-Application
and	O
Chrome.It	O
can	O
also	O
be	O
run	O
on	O
derived	O
browsers	O
,	O
such	O
as	O
Brave	B-Application
and	O
Microsoft	B-Application
Edge	I-Application
.	O
</s>
<s>
In	O
February	O
2023	O
a	O
thoroughly	O
upgraded	O
,	O
stand-alone	O
version	O
dubbed	O
Snowstorm	O
was	O
released	O
;	O
written	O
in	O
Rust	B-Application
and	O
funded	O
by	O
the	O
Open	O
Tech	O
Fund	O
,	O
beta	O
testing	O
is	O
by	O
invitation	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
package	O
containing	O
the	O
encrypted	O
text	O
of	O
this	O
article	O
would	O
be	O
labelled	O
with	O
the	O
destination	O
(	O
the	O
IP	B-Protocol
address	I-Protocol
of	O
the	O
reader	O
's	O
computer	O
)	O
,	O
and	O
the	O
source	O
(	O
the	O
IP	B-Protocol
address	I-Protocol
of	O
a	O
Wikipedia	O
server	O
)	O
.	O
</s>
<s>
By	O
contrast	O
,	O
Tor	B-Application
connections	O
relay	O
encrypted	O
traffic	O
though	O
a	O
chain	O
of	O
proxies	O
.	O
</s>
<s>
The	O
message	O
in	O
encrypted	O
in	O
layers	O
,	O
so	O
it	O
is	O
called	O
onion	B-Protocol
routing	I-Protocol
.	O
</s>
<s>
Since	O
the	O
source	O
of	O
the	O
content	O
is	O
hidden	O
behind	O
layers	O
of	O
proxy	B-Application
servers	I-Application
,	O
banned	O
sources	O
can	O
still	O
be	O
accessed	O
,	O
and	O
it	O
is	O
n't	O
clear	O
which	O
recipient	O
accessed	O
what	O
content	O
.	O
</s>
<s>
Since	O
Tor	B-Application
can	O
be	O
used	O
to	O
access	O
banned	O
websites	O
,	O
some	O
countries	O
,	O
such	O
as	O
Iran	O
and	O
Russia	O
,	O
ban	O
the	O
Tor	B-Application
network	I-Application
.	O
</s>
<s>
This	O
means	O
that	O
Tor	B-Application
users	O
ca	O
n't	O
simply	O
connect	O
to	O
a	O
publicly-known	O
Tor	B-Application
entry	O
node	O
;	O
all	O
known	O
Tor	B-Application
nodes	I-Application
will	O
be	O
blocked	O
by	O
the	O
censors	O
.	O
</s>
<s>
Instead	O
,	O
users	O
connect	O
to	O
a	O
Tor	B-Application
bridge	O
,	O
a	O
server	O
which	O
is	O
secretly	O
a	O
Tor	B-Application
entry	O
point	O
.	O
</s>
<s>
Censors	O
,	O
in	O
turn	O
,	O
seek	O
to	O
identify	O
and	O
block	O
Tor	B-Application
bridges	O
,	O
identifying	O
them	O
using	O
deep	B-Application
packet	I-Application
inspection	I-Application
.	O
</s>
<s>
Snowflake	B-Application
provides	O
a	O
large	O
number	O
of	O
ever-shifting	O
Tor	B-Application
entry	O
nodes	O
.	O
</s>
<s>
A	O
user	O
is	O
provided	O
with	O
the	O
IP	B-Protocol
address	I-Protocol
of	O
a	O
currently-active	O
Snowflake	B-Application
node	O
by	O
asking	O
a	O
broker	O
server	O
,	O
which	O
in	O
turn	O
uses	O
domain	O
fronting	O
to	O
pretend	O
to	O
be	O
a	O
major	O
website	O
.	O
</s>
<s>
The	O
user	O
then	O
talks	O
directly	O
to	O
the	O
Snowflake	B-Application
node	O
,	O
which	O
relays	O
into	O
the	O
Tor	B-Application
network	I-Application
.	O
</s>
<s>
A	O
Snowflake	B-Application
node	O
runs	O
whenever	O
the	O
browser	O
or	O
program	O
is	O
connected	O
to	O
the	O
internet	O
.	O
</s>
<s>
If	O
the	O
node	O
host	O
has	O
a	O
dynamic	O
IP	O
,	O
the	O
node	O
will	O
change	O
its	O
IP	B-Protocol
address	I-Protocol
over	O
time	O
.	O
</s>
<s>
See	O
also	O
ad	B-Protocol
hoc	I-Protocol
network	I-Protocol
.	O
</s>
<s>
Snowflake	B-Application
nodes	O
are	O
thus	O
used	O
as	O
Tor	B-Application
entry	O
nodes	O
,	O
not	O
as	O
exit	B-Application
nodes	I-Application
.	O
</s>
<s>
Exit	B-Application
nodes	I-Application
are	O
the	O
other	O
end	O
of	O
the	O
chain	O
.	O
</s>
<s>
They	O
are	O
the	O
Tor	B-Application
nodes	I-Application
that	O
know	O
what	O
content	O
was	O
requested	O
,	O
though	O
they	O
do	O
not	O
know	O
who	O
requested	O
it	O
(	O
for	O
instance	O
,	O
they	O
would	O
know	O
that	O
a	O
user	O
was	O
contacting	O
a	O
Wikipedia	O
server	O
,	O
but	O
they	O
would	O
not	O
know	O
the	O
IP	B-Protocol
address	I-Protocol
of	O
the	O
user	O
)	O
.	O
</s>
<s>
Exit	B-Application
nodes	I-Application
might	O
face	O
legal	O
action	O
in	O
the	O
country	O
in	O
which	O
they	O
are	O
hosted	O
if	O
they	O
relay	O
content	O
that	O
is	O
illegal	O
in	O
that	O
country	O
(	O
so	O
they	O
are	O
usually	O
run	O
in	O
countries	O
with	O
little	O
internet	O
censorship	O
)	O
.	O
</s>
<s>
It	O
is	O
unlikely	O
that	O
Snowflake	B-Application
node	O
hosts	O
could	O
face	O
such	O
liability	O
,	O
since	O
they	O
do	O
not	O
know	O
what	O
content	O
they	O
are	O
relaying	O
.	O
</s>
<s>
There	O
are	O
,	O
however	O
,	O
countries	O
where	O
using	O
Tor	B-Application
for	O
any	O
purpose	O
is	O
illegal	O
,	O
such	O
as	O
Russia	O
and	O
Iran	O
.	O
</s>
<s>
Snowflake	B-Application
uses	O
WebRTC	B-Protocol
to	O
allow	O
browsers	O
to	O
communicate	O
directly	O
with	O
one	O
another	O
.	O
</s>
<s>
Either	O
installing	O
a	O
browser	B-Protocol
extension	I-Protocol
,	O
or	O
keeping	O
a	O
tab	O
open	O
to	O
a	O
webpage	O
with	O
the	O
right	O
embedded	O
code	O
,	O
causes	O
one	O
's	O
browser	O
to	O
act	O
as	O
a	O
relay	O
.	O
</s>
<s>
Embedding	O
a	O
Snowflake	B-Application
badge	O
in	O
a	O
website	O
allows	O
visitors	O
to	O
make	O
their	O
browser	O
into	O
a	O
relay	O
,	O
exactly	O
as	O
installing	O
the	O
extension	O
does	O
,	O
but	O
by	O
clicking	O
a	O
button	O
on	O
the	O
website	O
rather	O
than	O
by	O
installing	O
software	O
.	O
</s>
<s>
Snowflake	B-Application
can	O
also	O
be	O
run	O
as	O
a	O
stand-alone	O
program	O
in	O
a	O
Docker	B-Language
container	O
.	O
</s>
<s>
A	O
detailed	O
technical	O
description	O
is	O
published	O
on	O
GitLab	B-Application
.	O
</s>
<s>
Countermeasures	O
believed	O
to	O
be	O
currently	O
in	O
use	O
against	O
Snowflake	B-Application
from	O
Russia	O
include	O
browser	B-Protocol
fingerprinting	I-Protocol
Snowflake	B-Application
hosts	O
and	O
then	O
blocking	O
them	O
.	O
</s>
<s>
Censors	O
may	O
also	O
install	O
and	O
use	O
Tor	B-Application
,	O
then	O
block	O
all	O
the	O
IP	B-Protocol
addresses	I-Protocol
offered	O
as	O
Snowflake	B-Application
servers	O
.	O
</s>
<s>
Censors	O
may	O
attempt	O
to	O
block	O
the	O
broker	O
's	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
To	O
circumvent	O
this	O
,	O
the	O
Snowflake	B-Application
client	O
utilizes	O
domain	O
fronting	O
.	O
</s>
<s>
If	O
overseas	O
connections	O
from	O
data	O
centers	O
are	O
allowed	O
,	O
but	O
residential	O
and	O
mobile	O
services	O
are	O
restricted	O
to	O
local	O
connections	O
,	O
then	O
Tor	B-Application
bridges	O
may	O
be	O
secretly	O
and	O
illegally	O
set	O
up	O
in	O
local	O
data	O
centers	O
.	O
</s>
<s>
When	O
a	O
country	O
shuts	O
down	O
access	O
to	O
foreign	O
internet	O
connections	O
altogether	O
,	O
essentially	O
cutting	O
the	O
country	O
off	O
from	O
the	O
global	O
internet	O
,	O
Snowflake	B-Application
becomes	O
useless	O
.	O
</s>
<s>
A	O
simple	O
proxy	O
,	O
like	O
a	O
virtual	B-Application
private	I-Application
network	I-Application
(	O
VPN	B-Application
)	O
,	O
has	O
only	O
a	O
single	O
relay	O
.	O
</s>
<s>
This	O
means	O
that	O
the	O
server	B-Protocol
address	I-Protocol
of	O
the	O
VPN	B-Application
has	O
to	O
be	O
known	O
to	O
every	O
user	O
,	O
making	O
it	O
easier	O
to	O
block	O
.	O
</s>
<s>
For	O
instance	O
,	O
at	O
the	O
beginning	O
of	O
October	O
2022	O
,	O
during	O
internet	O
disruptions	O
related	O
to	O
the	O
Mahsa	O
Amini	O
protests	O
,	O
VPNs	B-Application
in	O
Iran	O
would	O
drop	O
connections	O
every	O
few	O
minutes	O
.	O
</s>
<s>
The	O
VPN	B-Application
itself	O
also	O
knows	O
which	O
end-users	O
requested	O
which	O
pages	O
,	O
allowing	O
VPNs	B-Application
to	O
engage	O
in	O
surveillance	O
.	O
</s>
<s>
In	O
some	O
countries	O
,	O
such	O
as	O
Iran	O
,	O
VPNs	B-Application
are	O
illegal	O
and	O
may	O
be	O
government-affiliated	O
.	O
</s>
<s>
Snowflake	B-Application
came	O
to	O
be	O
widely	O
discussed	O
online	O
in	O
the	O
first	O
week	O
of	O
October	O
2022	O
,	O
as	O
a	O
way	O
of	O
combatting	O
internet	O
restrictions	O
in	O
Iran	O
during	O
the	O
Mahsa	O
Amini	O
protests	O
,	O
and	O
a	O
guide	O
in	O
Persian	O
was	O
released	O
.	O
</s>
<s>
In	O
2022	O
,	O
the	O
Russian	O
government	O
increased	O
efforts	O
to	O
block	O
access	O
to	O
Tor	B-Application
through	O
technical	O
and	O
political	O
means	O
,	O
and	O
the	O
Tor	B-Application
network	I-Application
reported	O
an	O
increase	O
in	O
traffic	O
from	O
Russia	O
using	O
Snowflake	B-Application
.	O
</s>
<s>
Snowflake	B-Application
is	O
integrated	O
into	O
the	O
Tor	B-Application
network	I-Application
.	O
</s>
<s>
Usage	O
of	O
the	O
Tor	B-Application
network	I-Application
is	O
becoming	O
more	O
common	O
in	O
Russia	O
,	O
Belarus	O
,	O
and	O
Iran	O
,	O
,	O
as	O
internet	O
censorship	O
in	O
these	O
countries	O
has	O
become	O
more	O
strict	O
.	O
</s>
