<s>
A	O
dark	B-Operating_System
net	I-Operating_System
or	O
darknet	B-Operating_System
is	O
an	O
overlay	B-Architecture
network	I-Architecture
within	O
the	O
Internet	O
that	O
can	O
only	O
be	O
accessed	O
with	O
specific	O
software	O
,	O
configurations	O
,	O
or	O
authorization	O
,	O
and	O
often	O
uses	O
a	O
unique	O
customized	O
communication	O
protocol	O
.	O
</s>
<s>
Two	O
typical	O
darknet	B-Operating_System
types	O
are	O
social	O
networks	O
(	O
usually	O
used	O
for	O
file	O
hosting	O
with	O
a	O
peer-to-peer	O
connection	O
)	O
,	O
and	O
anonymity	O
proxy	B-Application
networks	I-Application
such	O
as	O
Tor	B-Application
via	O
an	O
anonymized	O
series	O
of	O
connections	O
.	O
</s>
<s>
The	O
term	O
"	O
darknet	B-Operating_System
"	O
was	O
popularized	O
by	O
major	O
news	O
outlets	O
to	O
associate	O
with	O
Tor	B-Application
Onion	I-Application
services	O
,	O
when	O
the	O
infamous	O
drug	O
bazaar	O
Silk	O
Road	O
used	O
it	O
,	O
despite	O
the	O
terminology	O
being	O
unofficial	O
.	O
</s>
<s>
Technology	O
such	O
as	O
Tor	B-Application
,	O
I2P	B-Protocol
,	O
and	O
Freenet	B-Protocol
was	O
intended	O
to	O
defend	O
digital	O
rights	O
by	O
providing	O
security	O
,	O
anonymity	O
,	O
or	O
censorship	O
resistance	O
and	O
is	O
used	O
for	O
both	O
illegal	O
and	O
legitimate	O
reasons	O
.	O
</s>
<s>
Anonymous	O
communication	O
between	O
whistle-blowers	O
,	O
activists	O
,	O
journalists	O
and	O
news	O
organisations	O
is	O
also	O
facilitated	O
by	O
darknets	B-Operating_System
through	O
use	O
of	O
applications	O
such	O
as	O
SecureDrop	B-Application
.	O
</s>
<s>
Since	O
ARPANET	O
,	O
the	O
usage	O
of	O
dark	B-Operating_System
net	I-Operating_System
has	O
expanded	O
to	O
include	O
friend-to-friend	O
networks	O
(	O
usually	O
used	O
for	O
file	O
sharing	O
with	O
a	O
peer-to-peer	O
connection	O
)	O
and	O
privacy	O
networks	O
such	O
as	O
Tor	B-Application
.	O
</s>
<s>
The	O
reciprocal	O
term	O
for	O
a	O
darknet	B-Operating_System
is	O
a	O
clearnet	O
or	O
the	O
surface	O
web	O
when	O
referring	O
to	O
content	O
indexable	O
by	O
search	O
engines	O
.	O
</s>
<s>
The	O
term	O
"	O
darknet	B-Operating_System
"	O
is	O
often	O
used	O
interchangeably	O
with	O
"	O
dark	O
web	O
"	O
because	O
of	O
the	O
quantity	O
of	O
hidden	O
services	O
on	O
Tor	B-Application
's	O
darknet	B-Operating_System
.	O
</s>
<s>
Additionally	O
,	O
the	O
term	O
is	O
often	O
inaccurately	O
used	O
interchangeably	O
with	O
the	O
deep	O
web	O
because	O
of	O
Tor	B-Application
's	O
history	O
as	O
a	O
platform	O
that	O
could	O
not	O
be	O
search-indexed	O
.	O
</s>
<s>
"	O
Darknet	B-Operating_System
"	O
was	O
coined	O
in	O
the	O
1970s	O
to	O
designate	O
networks	O
isolated	O
from	O
ARPANET	O
(	O
the	O
government-founded	O
military/academical	O
network	O
which	O
evolved	O
into	O
the	O
Internet	O
)	O
,	O
for	O
security	O
purposes	O
.	O
</s>
<s>
Darknet	B-Operating_System
addresses	O
could	O
receive	O
data	O
from	O
ARPANET	O
but	O
did	O
not	O
appear	O
in	O
the	O
network	O
lists	O
and	O
would	O
not	O
answer	O
pings	B-Protocol
or	O
other	O
inquiries	O
.	O
</s>
<s>
The	O
term	O
gained	O
public	O
acceptance	O
following	O
publication	O
of	O
"	O
The	O
Darknet	B-Operating_System
and	O
the	O
Future	O
of	O
Content	O
Distribution	O
"	O
,	O
a	O
2002	O
paper	O
by	O
Peter	O
Biddle	O
,	O
Paul	O
England	O
,	O
Marcus	O
Peinado	O
,	O
and	O
Bryan	O
Willman	O
,	O
four	O
employees	O
of	O
Microsoft	O
who	O
argued	O
the	O
presence	O
of	O
the	O
darknet	B-Operating_System
was	O
the	O
primary	O
hindrance	O
to	O
the	O
development	O
of	O
workable	O
digital	O
rights	O
management	O
(	O
DRM	O
)	O
technologies	O
and	O
made	O
copyright	O
infringement	O
inevitable	O
.	O
</s>
<s>
This	O
paper	O
described	O
"	O
darknet	B-Operating_System
"	O
more	O
generally	O
as	O
any	O
type	O
of	O
parallel	O
network	O
that	O
is	O
encrypted	O
or	O
requires	O
a	O
specific	O
protocol	O
to	O
allow	O
a	O
user	O
to	O
connect	O
to	O
it	O
.	O
</s>
<s>
Journalist	O
J	O
.	O
D	O
.	O
Lasica	O
,	O
in	O
his	O
2005	O
book	O
Darknet	B-Operating_System
:	O
Hollywood	O
's	O
War	O
Against	O
the	O
Digital	O
Generation	O
,	O
described	O
the	O
darknet	B-Operating_System
's	O
reach	O
encompassing	O
file	O
sharing	O
networks	O
.	O
</s>
<s>
Subsequently	O
,	O
in	O
2014	O
,	O
journalist	O
Jamie	O
Bartlett	O
in	O
his	O
book	O
The	O
Dark	B-Operating_System
Net	I-Operating_System
used	O
the	O
term	O
to	O
describe	O
a	O
range	O
of	O
underground	O
and	O
emergent	O
subcultures	O
,	O
including	O
camgirls	O
,	O
cryptoanarchists	O
,	O
darknet	B-Operating_System
drug	O
markets	O
,	O
self	O
harm	O
communities	O
,	O
social	O
media	O
racists	O
,	O
and	O
transhumanists	O
.	O
</s>
<s>
Darknets	B-Operating_System
in	O
general	O
may	O
be	O
used	O
for	O
various	O
reasons	O
,	O
such	O
as	O
:	O
</s>
<s>
File	O
sharing	O
(	O
warez	B-Application
,	O
personal	O
files	O
,	O
pornography	O
,	O
confidential	O
files	O
,	O
illegal	O
or	O
counterfeit	O
software	O
,	O
etc	O
.	O
)	O
</s>
<s>
All	O
darknets	B-Operating_System
require	O
specific	O
software	O
installed	O
or	O
network	O
configurations	O
made	O
to	O
access	O
them	O
,	O
such	O
as	O
Tor	B-Application
,	O
which	O
can	O
be	O
accessed	O
via	O
a	O
customized	O
browser	O
from	O
Vidalia	B-Language
(	O
aka	O
the	O
Tor	B-Application
browser	O
bundle	O
)	O
,	O
or	O
alternatively	O
via	O
a	O
proxy	B-Application
configured	O
to	O
perform	O
the	O
same	O
function	O
.	O
</s>
<s>
Tor	B-Application
is	O
the	O
most	O
popular	O
instance	O
of	O
a	O
darknet	B-Operating_System
,	O
often	O
mistakenly	O
equated	O
with	O
darknet	B-Operating_System
in	O
general	O
.	O
</s>
<s>
anoNet	O
is	O
a	O
decentralized	O
friend-to-friend	O
network	O
built	O
using	O
VPN	B-Application
and	O
software	O
BGP	B-Protocol
routers	O
.	O
</s>
<s>
Decentralized	B-Application
network	I-Application
42	I-Application
(	O
not	O
for	O
anonymity	O
but	O
research	O
purposes	O
)	O
.	O
</s>
<s>
Freenet	B-Protocol
is	O
a	O
popular	O
DHT	B-Operating_System
file	O
hosting	O
darknet	B-Operating_System
platform	O
.	O
</s>
<s>
GNUnet	B-Language
can	O
be	O
utilized	O
as	O
a	O
darknet	B-Operating_System
if	O
the	O
"	O
F2F	O
(	O
network	O
)	O
topology	B-Architecture
"	O
option	O
is	O
enabled	O
.	O
</s>
<s>
I2P	B-Protocol
(	O
Invisible	B-Protocol
Internet	I-Protocol
Project	I-Protocol
)	O
is	O
an	O
overlay	B-Architecture
proxy	B-Application
network	O
that	O
features	O
hidden	O
services	O
called	O
"	O
Eepsites	O
"	O
.	O
</s>
<s>
IPFS	B-Protocol
has	O
a	O
browser	O
extension	O
that	O
may	O
backup	O
popular	O
webpages	O
.	O
</s>
<s>
RetroShare	B-Application
is	O
a	O
friend-to-friend	O
messenger	O
communication	O
and	O
file	O
transfer	O
platform	O
.	O
</s>
<s>
It	O
may	O
be	O
used	O
as	O
a	O
darknet	B-Operating_System
if	O
DHT	B-Operating_System
and	O
Discovery	O
features	O
are	O
disabled	O
.	O
</s>
<s>
Riffle	O
is	O
a	O
government	O
,	O
client-server	O
darknet	B-Operating_System
system	O
that	O
simultaneously	O
provides	O
secure	O
anonymity	O
(	O
as	O
long	O
as	O
at	O
least	O
one	O
server	O
remains	O
uncompromised	O
)	O
,	O
efficient	O
computation	O
,	O
and	O
minimal	O
bandwidth	O
burden	O
.	O
</s>
<s>
Syndie	B-Language
is	O
software	O
used	O
to	O
publish	O
distributed	B-Architecture
forums	O
over	O
the	O
anonymous	O
networks	O
of	O
I2P	B-Protocol
,	O
Tor	B-Application
and	O
Freenet	B-Protocol
.	O
</s>
<s>
Tor	B-Application
(	O
The	B-Application
onion	I-Application
router	I-Application
)	O
is	O
an	O
anonymity	B-Application
network	I-Application
that	O
also	O
features	O
a	O
darknet	B-Operating_System
–	O
via	O
its	O
onion	O
services	O
.	O
</s>
<s>
Tribler	B-Language
is	O
an	O
anonymous	O
BitTorrent	O
client	O
with	O
built	O
in	O
search	O
engine	O
,	O
and	O
non-web	O
,	O
worldwide	O
publishing	O
through	O
channels	O
.	O
</s>
<s>
Urbit	O
is	O
a	O
federated	O
system	O
of	O
personal	O
servers	O
in	O
a	O
peer-to-peer	O
overlay	B-Architecture
network	I-Architecture
.	O
</s>
<s>
Zeronet	B-Protocol
is	O
a	O
DHT	B-Operating_System
Web	O
2.0	O
hosting	O
with	O
Tor	B-Application
users	O
.	O
</s>
