<s>
Internet	B-Application
censorship	I-Application
circumvention	I-Application
is	O
the	O
use	O
of	O
various	O
methods	O
and	O
tools	O
to	O
bypass	O
internet	B-Application
censorship	I-Application
.	O
</s>
<s>
Various	O
techniques	O
and	O
methods	O
are	O
used	O
to	O
bypass	O
Internet	B-Application
censorship	I-Application
,	O
and	O
have	O
differing	O
ease	O
of	O
use	O
,	O
speed	O
,	O
security	O
,	O
and	O
risks	O
.	O
</s>
<s>
Some	O
methods	O
,	O
such	O
as	O
the	O
use	O
of	O
alternate	O
DNS	B-Protocol
servers	I-Protocol
,	O
evade	O
blocking	O
by	O
using	O
an	O
alternate	O
address	O
or	O
address	O
lookup	O
system	O
to	O
access	O
the	O
site	O
.	O
</s>
<s>
Additionally	O
,	O
there	O
are	O
solutions	O
that	O
rely	O
on	O
gaining	O
access	O
to	O
an	O
Internet	O
connection	O
that	O
is	O
not	O
subject	O
to	O
filtering	O
,	O
often	O
in	O
a	O
different	O
jurisdiction	O
not	O
subject	O
to	O
the	O
same	O
censorship	O
laws	O
,	O
using	O
technologies	O
such	O
as	O
proxying	B-Application
,	O
virtual	B-Application
private	I-Application
networks	I-Application
,	O
or	O
anonymization	O
networks	O
.	O
</s>
<s>
There	O
are	O
many	O
methods	O
available	O
that	O
may	O
allow	O
the	O
circumvention	O
of	O
Internet	B-Protocol
filtering	I-Protocol
,	O
which	O
can	O
widely	O
vary	O
in	O
terms	O
of	O
implementation	O
difficulty	O
,	O
effectiveness	O
,	O
and	O
resistance	O
to	O
detection	O
.	O
</s>
<s>
Filters	O
may	O
block	O
specific	O
domain	O
names	O
,	O
either	O
using	O
DNS	B-Protocol
hijacking	I-Protocol
or	O
URL	O
filtering	O
.	O
</s>
<s>
If	O
DNS	B-Protocol
resolution	O
is	O
disrupted	O
but	O
the	O
site	O
is	O
not	O
blocked	O
in	O
other	O
ways	O
,	O
it	O
may	O
be	O
possible	O
to	O
access	O
a	O
site	O
directly	O
through	O
its	O
IP	B-Protocol
address	I-Protocol
or	O
modifying	O
the	O
host	B-Protocol
file	I-Protocol
.	I-Protocol
</s>
<s>
Using	O
alternative	O
DNS	B-Protocol
servers	I-Protocol
,	O
or	O
public	B-Operating_System
recursive	I-Operating_System
name	I-Operating_System
servers	I-Operating_System
(	O
especially	O
when	O
used	O
through	O
an	O
encrypted	O
DNS	B-Protocol
client	O
)	O
,	O
may	O
bypass	O
DNS-based	O
blocking	O
.	O
</s>
<s>
Censors	O
may	O
block	O
specific	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
Depending	O
on	O
how	O
the	O
filtering	O
is	O
implemented	O
,	O
it	O
may	O
be	O
possible	O
to	O
use	O
different	O
forms	O
of	O
the	O
IP	B-Protocol
address	I-Protocol
,	O
such	O
as	O
by	O
specifying	O
the	O
address	O
in	O
a	O
different	O
base	O
.	O
</s>
<s>
Blockchain	B-Application
technology	I-Application
is	O
an	O
attempt	O
to	O
decentralize	O
namespaces	O
outside	O
the	O
control	O
of	O
a	O
single	O
entity	O
.	O
</s>
<s>
Cached	B-Protocol
pages	I-Protocol
:	O
Some	O
search	O
engines	O
keep	O
copies	O
of	O
previously	O
indexed	O
webpages	O
,	O
or	O
cached	B-Protocol
pages	I-Protocol
,	O
which	O
are	O
often	O
hosted	O
by	O
search	O
engines	O
and	O
may	O
not	O
be	O
blocked	O
.	O
</s>
<s>
For	O
example	O
,	O
Google	B-Application
allows	O
the	O
retrieval	O
of	O
cached	B-Protocol
pages	I-Protocol
by	O
entering	O
"	O
cache:some-url	O
"	O
as	O
a	O
search	O
request	O
.	O
</s>
<s>
The	O
Docker	B-Language
Registry	O
Image	O
Repository	O
is	O
a	O
centralized	O
storage	O
,	O
application	O
stateless	O
,	O
and	O
node	B-Protocol
scalable	O
HTTP	B-Protocol
public	O
service	O
and	O
has	O
a	O
performance	O
bottleneck	O
in	O
the	O
multinational	O
upload	O
and	O
download	O
scenario	O
.	O
</s>
<s>
Decentralized	O
Docker	B-Language
Registry	O
avoids	O
this	O
centralization	O
drawback	O
.	O
</s>
<s>
DDR	O
uses	O
a	O
network-structured	O
P2P	O
network	O
to	O
store	O
and	O
query	O
mirror	O
manifest	O
file	O
and	O
blob	O
routing	O
,	O
while	O
each	O
node	B-Protocol
serves	O
as	O
an	O
independent	O
mirror	O
repository	O
to	O
provide	O
mirror	O
upload	O
and	O
download	O
for	O
the	O
entire	O
network	O
.	O
</s>
<s>
RSS	O
aggregators	O
:	O
RSS	O
aggregators	O
such	O
as	O
Feedly	B-Application
may	O
be	O
able	O
to	O
receive	O
and	O
pass	O
on	O
RSS	O
feeds	O
that	O
are	O
blocked	O
when	O
accessed	O
directly	O
.	O
</s>
<s>
Napster	B-Application
was	O
the	O
first	O
peer	O
to	O
peer	O
platform	O
but	O
got	O
technically	O
closed	O
due	O
to	O
centralized	O
bootstrapping	O
vulnerabilities	O
.	O
</s>
<s>
Gnutella	B-Protocol
was	O
the	O
first	O
sustainable	O
hosting	O
by	O
decentralization	O
.	O
</s>
<s>
Freenet	B-Protocol
's	I-Protocol
model	O
is	O
that	O
"	O
true	O
freedom	O
requires	O
true	O
anonymity.	O
"	O
</s>
<s>
Later	O
BitTorrent	B-Protocol
was	O
developed	O
to	O
allocate	O
resources	O
with	O
high	O
performance	O
and	O
fairness	O
.	O
</s>
<s>
ZeroNet	B-Protocol
was	O
the	O
first	O
DHT	B-Operating_System
to	O
support	O
dynamic	O
and	O
updateable	O
webpages	O
.	O
</s>
<s>
YaCy	B-Application
is	O
the	O
leading	O
distributed	O
search	O
.	O
</s>
<s>
Anonymity	B-Application
Networks	I-Application
:	O
The	O
anonymity	O
Tor	B-Application
Onion	I-Application
and	O
I2P	B-Protocol
provides	O
leads	O
to	O
more	O
willingness	O
to	O
host	O
content	O
that	O
would	O
otherwise	O
be	O
censored	O
.	O
</s>
<s>
Federated	O
:	O
Being	O
semi-decentralised	O
,	O
federated	O
platforms	O
such	O
as	O
Nextcloud	B-General_Concept
and	O
IRC	O
make	O
it	O
easier	O
for	O
users	O
to	O
find	O
an	O
instance	O
where	O
they	O
are	O
welcomed	O
.	O
</s>
<s>
Web	O
proxies	O
:	O
Proxy	B-Application
websites	I-Application
are	O
configured	O
to	O
allow	O
users	O
to	O
load	O
external	O
web	O
pages	O
through	O
the	O
proxy	B-Application
server	I-Application
,	O
permitting	O
the	O
user	O
to	O
load	O
the	O
page	O
as	O
if	O
it	O
is	O
coming	O
from	O
the	O
proxy	B-Application
server	I-Application
and	O
not	O
the	O
(	O
blocked	O
)	O
source	O
.	O
</s>
<s>
However	O
,	O
depending	O
on	O
how	O
the	O
proxy	O
is	O
configured	O
,	O
a	O
censor	O
may	O
be	O
able	O
to	O
determine	O
the	O
pages	O
loaded	O
and/or	O
determine	O
that	O
the	O
user	O
is	O
using	O
a	O
proxy	B-Application
server	I-Application
.	O
</s>
<s>
For	O
example	O
,	O
the	O
mobile	O
Opera	B-Protocol
Mini	I-Protocol
browser	O
uses	O
a	O
proxy-based	O
approach	O
employing	O
encryption	O
and	O
compression	O
in	O
order	O
to	O
speed	O
up	O
downloads	O
.	O
</s>
<s>
This	O
has	O
the	O
side	O
effect	O
of	O
allowing	O
it	O
to	O
circumvent	O
several	O
approaches	O
to	O
Internet	B-Application
censorship	I-Application
.	O
</s>
<s>
Domain	O
fronting	O
:	O
Circumvention	O
software	O
can	O
implement	O
a	O
technique	O
called	O
domain	O
fronting	O
,	O
where	O
the	O
destination	O
of	O
a	O
connection	O
is	O
hidden	O
by	O
passing	O
the	O
initial	O
requests	O
through	O
a	O
content	B-Operating_System
delivery	I-Operating_System
network	I-Operating_System
or	O
other	O
popular	O
site	O
which	O
censors	O
may	O
be	O
unwilling	O
to	O
block	O
.	O
</s>
<s>
This	O
technique	O
was	O
used	O
by	O
messaging	O
applications	O
including	O
Signal	O
and	O
Telegram	B-Application
.	O
</s>
<s>
Tor	B-Application
's	O
meek	O
uses	O
Microsoft	O
's	O
Azure	O
cloud	O
.	O
</s>
<s>
However	O
,	O
large	O
cloud	O
providers	O
such	O
as	O
Amazon	B-Application
Web	I-Application
Services	I-Application
and	O
Google	B-General_Concept
Cloud	I-General_Concept
no	O
longer	O
permit	O
its	O
use	O
.	O
</s>
<s>
SSH	B-Protocol
tunneling	O
:	O
By	O
establishing	O
an	O
SSH	B-Protocol
tunnel	I-Protocol
,	O
a	O
user	O
can	O
forward	O
all	O
their	O
traffic	O
over	O
an	O
encrypted	O
channel	O
,	O
so	O
both	O
outgoing	O
requests	O
for	O
blocked	O
sites	O
and	O
the	O
response	O
from	O
those	O
sites	O
are	O
hidden	O
from	O
the	O
censors	O
,	O
for	O
whom	O
it	O
appears	O
as	O
unreadable	O
SSH	B-Protocol
traffic	O
.	O
</s>
<s>
Virtual	B-Application
private	I-Application
network	I-Application
(	O
VPN	B-Application
)	O
:	O
Using	O
a	O
VPN	B-Application
,	O
A	O
user	O
who	O
experiences	O
internet	B-Application
censorship	I-Application
can	O
create	O
a	O
secure	O
connection	O
to	O
a	O
more	O
permissive	O
country	O
,	O
and	O
browse	O
the	O
internet	O
as	O
if	O
they	O
were	O
situated	O
in	O
that	O
country	O
.	O
</s>
<s>
According	O
to	O
GlobalWebIndex	O
in	O
2014	O
,	O
there	O
were	O
over	O
400	O
million	O
people	O
use	O
virtual	B-Application
private	I-Application
networks	I-Application
to	O
circumvent	O
censorship	O
or	O
for	O
increased	O
level	O
of	O
privacy	O
although	O
this	O
number	O
is	O
not	O
verifiable	O
.	O
</s>
<s>
Tor	B-Application
:	O
More	O
advanced	O
tools	O
such	O
as	O
Tor	B-Application
route	O
encrypted	O
traffic	O
through	O
multiple	O
servers	O
to	O
make	O
the	O
source	O
and	O
destination	O
of	O
traffic	O
less	O
traceable	O
.	O
</s>
<s>
A	O
censor	O
may	O
be	O
able	O
to	O
detect	O
and	O
block	O
use	O
of	O
circumvention	O
tools	O
through	O
Deep	B-Application
Packet	I-Application
Inspection	I-Application
.	O
</s>
<s>
Tor	B-Application
and	O
other	O
circumvention	O
tools	O
have	O
adopted	O
multiple	O
obfuscation	O
techniques	O
that	O
users	O
can	O
use	O
depending	O
on	O
the	O
nature	O
of	O
their	O
connection	O
,	O
which	O
are	O
sometimes	O
called	O
"	O
Pluggable	O
Transports	O
"	O
.	O
</s>
<s>
Functionality	O
that	O
people	O
may	O
be	O
after	O
might	O
overlap	O
with	O
non-internet	O
services	O
,	O
such	O
as	O
traditional	O
post	O
,	O
Bluetooth	O
,	O
or	O
wakie-talkie	B-Application
.	O
</s>
<s>
A	O
2010	O
study	O
by	O
Harvard	O
University	O
researchers	O
estimated	O
that	O
very	O
few	O
users	O
use	O
censorship	B-Application
circumvention	I-Application
tools	O
—	O
likely	O
less	O
than	O
3%	O
of	O
users	O
even	O
in	O
countries	O
that	O
consistently	O
implement	O
widespread	O
censorship	O
.	O
</s>
<s>
Other	O
studies	O
have	O
pointed	O
out	O
that	O
efforts	O
to	O
block	O
circumvention	O
tools	O
in	O
China	O
have	O
reduced	O
adoption	O
of	O
those	O
tools	O
;	O
the	O
Tor	B-Application
network	I-Application
previously	O
had	O
over	O
30,000	O
users	O
connecting	O
from	O
China	O
but	O
as	O
of	O
2014	O
had	O
only	O
approximately	O
3,000	O
Chinese	O
users	O
.	O
</s>
<s>
In	O
Thailand	O
,	O
internet	B-Application
censorship	I-Application
has	O
existed	O
since	O
2002	O
,	O
and	O
there	O
is	O
sporadic	O
and	O
inconsistent	O
filtering	O
.	O
</s>
<s>
In	O
response	O
to	O
the	O
2014	O
blocking	O
of	O
Twitter	O
in	O
Turkey	O
,	O
information	O
about	O
alternate	O
DNS	B-Protocol
servers	I-Protocol
was	O
widely	O
shared	O
,	O
as	O
using	O
another	O
DNS	B-Protocol
server	I-Protocol
such	O
as	O
Google	B-Protocol
Public	I-Protocol
DNS	I-Protocol
allowed	O
users	O
to	O
access	O
Twitter	O
.	O
</s>
<s>
After	O
an	O
April	O
2018	O
ban	O
on	O
the	O
Telegram	B-Application
messaging	O
app	O
in	O
Iran	O
,	O
web	O
searches	O
for	O
VPN	B-Application
and	O
other	O
circumvention	O
software	O
increased	O
as	O
much	O
as	O
48×	O
for	O
some	O
search	O
terms	O
,	O
but	O
there	O
was	O
evidence	O
that	O
users	O
were	O
downloading	O
unsafe	O
software	O
.	O
</s>
<s>
As	O
many	O
as	O
a	O
third	O
of	O
Iranian	O
internet	O
users	O
used	O
the	O
Psiphon	B-Application
tool	O
in	O
the	O
days	O
immediately	O
following	O
the	O
block	O
,	O
and	O
in	O
June	O
2018	O
as	O
many	O
as	O
3.5	O
million	O
Iranian	O
users	O
continued	O
to	O
use	O
the	O
tool	O
.	O
</s>
<s>
It	O
is	O
important	O
to	O
understand	O
that	O
open	O
public	O
proxy	B-Application
sites	I-Application
do	O
not	O
provide	O
anonymity	O
and	O
can	O
view	O
and	O
record	O
the	O
location	O
of	O
computers	O
making	O
requests	O
as	O
well	O
as	O
the	O
websites	O
accessed	O
.	O
</s>
<s>
There	O
are	O
five	O
general	O
types	O
of	O
Internet	B-Application
censorship	I-Application
circumvention	I-Application
software	O
:	O
</s>
<s>
CGI	B-Language
proxies	O
use	O
a	O
script	O
running	O
on	O
a	O
web	B-Application
server	I-Application
to	O
perform	O
the	O
proxying	B-Application
function	O
.	O
</s>
<s>
A	O
CGI	B-Language
proxy	O
client	O
sends	O
the	O
requested	O
url	O
embedded	O
within	O
the	O
data	O
portion	O
of	O
an	O
HTTP	B-Protocol
request	O
to	O
the	O
CGI	B-Language
proxy	B-Application
server	I-Application
.	O
</s>
<s>
The	O
CGI	B-Language
proxy	B-Application
server	I-Application
pulls	O
the	O
ultimate	O
destination	O
information	O
from	O
the	O
data	O
embedded	O
in	O
the	O
HTTP	B-Protocol
request	O
,	O
sends	O
out	O
its	O
own	O
HTTP	B-Protocol
request	O
to	O
the	O
ultimate	O
destination	O
,	O
and	O
then	O
returns	O
the	O
result	O
to	O
the	O
proxy	O
client	O
.	O
</s>
<s>
A	O
CGI	B-Language
proxy	O
tool	O
's	O
security	O
can	O
be	O
trusted	O
as	O
far	O
as	O
the	O
operator	O
of	O
the	O
proxy	B-Application
server	I-Application
can	O
be	O
trusted	O
.	O
</s>
<s>
CGI	B-Language
proxy	O
tools	O
require	O
no	O
manual	O
configuration	O
of	O
the	O
browser	O
or	O
client	O
software	O
installation	O
,	O
but	O
they	O
do	O
require	O
that	O
the	O
user	O
use	O
an	O
alternative	O
,	O
potentially	O
confusing	O
browser	O
interface	O
within	O
the	O
existing	O
browser	O
.	O
</s>
<s>
HTTP	B-Protocol
proxies	O
send	O
HTTP	B-Protocol
requests	I-Protocol
through	O
an	O
intermediate	O
proxying	B-Application
server	O
.	O
</s>
<s>
A	O
client	O
connecting	O
through	O
a	O
HTTP	B-Protocol
proxy	O
sends	O
exactly	O
the	O
same	O
HTTP	B-Protocol
request	O
to	O
the	O
proxy	O
as	O
it	O
would	O
send	O
to	O
the	O
destination	O
server	O
unproxied	O
.	O
</s>
<s>
The	O
HTTP	B-Protocol
proxy	O
parses	O
the	O
HTTP	B-Protocol
request	O
;	O
sends	O
its	O
own	O
HTTP	B-Protocol
request	O
to	O
the	O
ultimate	O
destination	O
server	O
;	O
and	O
then	O
returns	O
the	O
response	O
back	O
to	O
the	O
proxy	O
client	O
.	O
</s>
<s>
An	O
HTTP	B-Protocol
proxy	O
tool	O
's	O
security	O
can	O
be	O
trusted	O
as	O
far	O
as	O
the	O
operator	O
of	O
the	O
proxy	B-Application
server	I-Application
can	O
be	O
trusted	O
.	O
</s>
<s>
HTTP	B-Protocol
proxy	O
tools	O
require	O
either	O
manual	O
configuration	O
of	O
the	O
browser	O
or	O
client	O
side	O
software	O
that	O
can	O
configure	O
the	O
browser	O
for	O
the	O
user	O
.	O
</s>
<s>
Once	O
configured	O
,	O
an	O
HTTP	B-Protocol
proxy	O
tool	O
allows	O
the	O
user	O
transparently	O
to	O
use	O
his	O
normal	O
browser	O
interface	O
.	O
</s>
<s>
Application	O
proxies	O
are	O
similar	O
to	O
HTTP	B-Protocol
proxies	O
,	O
but	O
support	O
a	O
wider	O
range	O
of	O
online	O
applications	O
.	O
</s>
<s>
Re-routing	O
systems	O
send	O
requests	O
and	O
responses	O
through	O
a	O
series	O
of	O
proxying	B-Application
servers	O
,	O
encrypting	O
the	O
data	O
again	O
at	O
each	O
proxy	O
,	O
so	O
that	O
a	O
given	O
proxy	O
knows	O
at	O
most	O
either	O
where	O
the	O
data	O
came	O
from	O
or	O
is	O
going	O
to	O
,	O
but	O
not	O
both	O
.	O
</s>
<s>
This	O
decreases	O
the	O
amount	O
of	O
trust	O
required	O
of	O
the	O
individual	O
proxy	O
hosts	B-Protocol
.	O
</s>
<s>
Below	O
is	O
a	O
list	O
of	O
different	O
Internet	B-Application
censorship	I-Application
circumvention	I-Application
software	O
:	O
</s>
<s>
Name	O
Type	O
Developer	O
Cost	O
Web	O
site	O
Notes	O
alkasir	O
"	O
About	O
alkasir	O
"	O
,	O
alkasir.com,	O
accessed	O
16	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
Yemeni	O
journalist	O
Walid	O
al-Saqaf	O
free	O
www.alkasir.com	O
Uses	O
'	O
split-tunneling	O
'	O
to	O
only	O
redirect	O
to	O
proxy	B-Application
servers	I-Application
when	O
blocking	O
is	O
encountered	O
.	O
</s>
<s>
Anonymizerwww.anonymizer.com/	O
,	O
Anonymizer	O
,	O
Inc.	O
,	O
accessed	O
16	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
Anonymizer	O
,	O
Inc	O
.	O
paid	O
www.anonymizer.com/	O
Transparently	O
tunnels	O
traffic	O
through	O
Anonymizer	O
.	O
</s>
<s>
CGIProxyCGIProxy	O
"	O
,	O
James	O
Marshall	O
,	O
accessed	O
17	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
James	O
Marshall	O
free	O
www.jmarshall.com/	O
Turn	O
a	O
computer	O
into	O
a	O
personal	O
,	O
encrypted	O
proxy	B-Application
server	I-Application
capable	O
of	O
retrieving	O
and	O
displaying	O
web	O
pages	O
to	O
users	O
of	O
the	O
server	O
.	O
</s>
<s>
CGIProxy	B-Language
is	O
the	O
engine	O
used	O
by	O
many	O
other	O
circumvention	O
systems	O
.	O
</s>
<s>
Flash	B-Application
proxy	I-Application
"	O
Flash	B-Application
proxies	I-Application
"	O
,	O
Applied	O
Crypto	O
Group	O
in	O
the	O
Computer	O
Science	O
Department	O
at	O
Stanford	O
University	O
,	O
accessed	O
21	O
March	O
2013	O
HTTP	B-Protocol
proxy	O
Stanford	O
University	O
free	O
Uses	O
ephemeral	O
browser-based	O
proxy	O
relays	O
to	O
connect	O
to	O
the	O
Tor	B-Application
network	I-Application
.	O
</s>
<s>
Freegate	B-Application
"	O
About	O
D.I.T.	O
"	O
</s>
<s>
,	O
Dynamic	O
Internet	O
Technology	O
,	O
accessed	O
16	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
Dynamic	O
Internet	O
Technology	O
,	O
Inc	O
.	O
free	O
www.dit-inc.us	O
Uses	O
a	O
range	O
of	O
open	B-Protocol
proxies	I-Protocol
to	O
access	O
blocked	O
web	O
sites	O
via	O
DIT	O
's	O
DynaWeb	O
anti-censorship	O
network	O
.	O
</s>
<s>
Freenet	B-Protocol
"	O
What	O
is	O
Freenet	B-Protocol
?	O
"	O
</s>
<s>
,	O
The	O
Freenet	B-Protocol
Project	I-Protocol
,	O
accessed	O
16	O
September	O
2011	O
peer-to-peer	O
Ian	O
Clarke	O
free	O
freenetproject.org	O
A	O
decentralized	O
,	O
distributed	O
data	O
store	O
using	O
contributed	O
bandwidth	O
and	O
storage	O
space	O
of	O
member	O
computers	O
to	O
provide	O
strong	O
anonymity	O
protection	O
.	O
</s>
<s>
I2P	B-Protocol
"	O
I2P	B-Protocol
Anonymous	O
Network	O
"	O
,	O
I2P	B-Protocol
Project	O
,	O
accessed	O
16	O
September	O
2011	O
(	O
originally	O
Invisible	B-Protocol
Internet	I-Protocol
Project	I-Protocol
)	O
re-routing	O
I2P	B-Protocol
Project	O
free	O
geti2p.net	O
Uses	O
a	O
pseudonymous	O
overlay	O
network	O
to	O
allow	O
anonymous	O
web	O
browsing	O
,	O
chatting	O
,	O
file	O
transfers	O
,	O
amongst	O
other	O
features	O
.	O
</s>
<s>
Java	B-Language
Anon	I-Language
Proxy	I-Language
"	O
Revocable	O
Anonymity	O
"	O
,	O
Stefan	O
Köpsell	O
,	O
Rolf	O
Wendolsky	O
,	O
Hannes	O
Federrath	O
,	O
in	O
Proc	O
.	O
</s>
<s>
)	O
,	O
ETRICS	O
2006	O
,	O
Freiburg	O
,	O
Germany	O
,	O
6	O
–	O
9	O
June	O
2006	O
,	O
LNCS	O
3995	O
,	O
Springer-Verlag	O
,	O
Heidelberg	O
2006	O
,	O
pp.206-220	O
(	O
also	O
known	O
as	O
JAP	O
or	O
JonDonym	B-Language
)	O
re-routing	O
(	O
fixed	O
)	O
Jondos	O
GmbH	O
free	O
or	O
paid	O
anonymous-proxy-servers.net	O
Uses	O
the	O
underlying	O
anonymity	O
service	O
AN.ON	O
to	O
allow	O
browsing	O
with	O
revocable	O
pseudonymity	O
.	O
</s>
<s>
Psiphon	B-Application
"	O
About	O
Psiphon	B-Application
"	O
,	O
Psiphon	B-Application
,	O
Inc.	O
,	O
4	O
April	O
2011	O
"	O
Psiphon	B-Application
Content	O
Delivery	O
Software	O
"	O
,	O
Launchpad	O
,	O
accessed	O
16	O
September	O
2011	O
CGI	B-Language
proxy	O
Psiphon	B-Application
,	O
Inc	O
.	O
free	O
psiphon.ca	O
A	O
simple-to-administer	O
,	O
open-source	O
Internet	B-Application
censorship	I-Application
circumvention	I-Application
system	O
in	O
wide-scale	O
use	O
,	O
with	O
a	O
cloud-based	O
infrastructure	O
serving	O
millions	O
.	O
</s>
<s>
Proxify	B-Application
"	O
About	O
Proxify	B-Application
"	O
,	O
UpsideOut	O
,	O
Inc.	O
,	O
accessed	O
17	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
UpsideOut	O
,	O
Inc	O
.	O
free	O
or	O
paid	O
proxify.com/	O
An	O
encrypted	O
,	O
public	O
,	O
web-based	O
circumvention	O
system	O
.	O
</s>
<s>
StupidCensorshipAbout	O
StupidCensorship.com,	O
Peacefire	O
,	O
accessed	O
17	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
Peacefire	O
free	O
stupidcensorship.com/	O
An	O
encrypted	O
,	O
public	O
,	O
web-based	O
circumvention	O
system	O
.	O
</s>
<s>
Tor	B-Application
"	O
Tor	B-Application
:	O
Overview	O
"	O
,	O
The	O
Tor	B-Application
Project	I-Application
,	O
Inc.	O
,	O
accessed	O
16	O
September	O
2011	O
re-routing	O
(	O
randomized	O
)	O
The	O
Tor	B-Application
Project	I-Application
free	O
www.torproject.org	O
Allows	O
users	O
to	O
bypass	O
Internet	B-Application
censorship	I-Application
while	O
providing	O
strong	O
anonymity	O
.	O
</s>
<s>
Ultrasurf	B-Application
"	O
About	O
UltraReach	B-Application
"	O
,	O
Ultrareach	B-Application
Internet	O
Corp.	O
,	O
accessed	O
16	O
September	O
2011	O
HTTP	B-Protocol
proxy	O
Ultrareach	B-Application
Internet	O
Corporation	O
free	O
www.ultrasurf.us/	O
Anti-censorship	O
product	O
that	O
allows	O
users	O
in	O
countries	O
with	O
heavy	O
internet	B-Application
censorship	I-Application
to	O
protect	O
their	O
internet	O
privacy	O
and	O
security	O
.	O
</s>
