<s>
The	O
internationalized	B-Language
domain	I-Language
name	I-Language
(	O
IDN	O
)	O
homograph	B-General_Concept
attack	I-General_Concept
is	O
a	O
way	O
a	O
malicious	O
party	O
may	O
deceive	O
computer	O
users	O
about	O
what	O
remote	O
system	O
they	O
are	O
communicating	O
with	O
,	O
by	O
exploiting	O
the	O
fact	O
that	O
many	O
different	O
characters	O
look	O
alike	O
(	O
i.e.	O
,	O
they	O
are	O
homographs	O
,	O
hence	O
the	O
term	O
for	O
the	O
attack	O
,	O
although	O
technically	O
homoglyph	O
is	O
the	O
more	O
accurate	O
term	O
for	O
different	O
characters	O
that	O
look	O
alike	O
)	O
.	O
</s>
<s>
This	O
kind	O
of	O
spoofing	O
attack	O
is	O
also	O
known	O
as	O
script	B-General_Concept
spoofing	I-General_Concept
.	O
</s>
<s>
Unicode	O
incorporates	O
numerous	O
writing	O
systems	O
,	O
and	O
,	O
for	O
a	O
number	O
of	O
reasons	O
,	O
similar-looking	O
characters	O
such	O
as	O
Greek	O
Ο	O
,	O
Latin	O
O	B-Language
,	O
and	O
Cyrillic	O
О	O
were	O
not	O
assigned	O
the	O
same	O
code	O
.	O
</s>
<s>
The	O
registration	O
of	O
homographic	O
domain	O
names	O
is	O
akin	O
to	O
typosquatting	B-Protocol
,	O
in	O
that	O
both	O
forms	O
of	O
attacks	O
use	O
a	O
similar-looking	O
name	O
to	O
a	O
more	O
established	O
domain	O
to	O
fool	O
a	O
user	O
.	O
</s>
<s>
The	O
major	O
difference	O
is	O
that	O
in	O
typosquatting	B-Protocol
the	O
perpetrator	O
attracts	O
victims	O
by	O
relying	O
on	O
natural	O
typographical	O
errors	O
commonly	O
made	O
when	O
manually	O
entering	O
a	O
URL	O
,	O
while	O
in	O
homograph	O
spoofing	O
the	O
perpetrator	O
deceives	O
the	O
victims	O
by	O
presenting	O
visually	O
indistinguishable	O
hyperlinks	O
.	O
</s>
<s>
There	O
are	O
cases	O
in	O
which	O
a	O
registration	O
can	O
be	O
both	O
typosquatting	B-Protocol
and	O
homograph	O
spoofing	O
;	O
the	O
pairs	O
of	O
l/I	O
,	O
i/j	O
,	O
and	O
0/O	O
are	O
all	O
both	O
close	O
together	O
on	O
keyboards	O
and	O
,	O
depending	O
on	O
the	O
typeface	O
,	O
may	O
be	O
difficult	O
or	O
impossible	O
to	O
distinguish	O
.	O
</s>
<s>
An	O
early	O
nuisance	O
of	O
this	O
kind	O
,	O
pre-dating	O
the	O
Internet	O
and	O
even	O
text	O
terminals	O
,	O
was	O
the	O
confusion	O
between	O
"	O
l	O
"	O
(	O
lowercase	O
letter	O
"	O
L	O
"	O
)	O
/	O
"	O
1	O
"	O
(	O
the	O
number	O
"	O
one	O
"	O
)	O
and	O
"	O
O	B-Language
"	O
(	O
capital	O
letter	O
for	O
vowel	O
"	O
o	B-Language
"	O
)	O
/	O
"	O
0	O
"	O
(	O
the	O
number	O
"	O
zero	O
"	O
)	O
.	O
</s>
<s>
The	O
zero/o	O
confusion	O
gave	O
rise	O
to	O
the	O
tradition	O
of	O
crossing	O
zeros	O
,	O
so	O
that	O
a	O
computer	O
operator	O
would	O
type	O
them	O
correctly	O
.	O
</s>
<s>
The	O
translation	O
from	O
the	O
Arabic	O
"	O
samt	O
"	O
included	O
the	O
scribe	O
's	O
confusing	O
of	O
"	O
m	B-Language
"	O
into	O
"	O
ni	O
"	O
.	O
</s>
<s>
This	O
was	O
common	O
in	O
medieval	O
blackletter	O
,	O
which	O
did	O
not	O
connect	O
the	O
vertical	O
columns	O
on	O
the	O
letters	O
i	O
,	O
m	B-Language
,	O
n	B-Application
,	O
or	O
u	O
,	O
making	O
them	O
difficult	O
to	O
distinguish	O
when	O
several	O
were	O
in	O
a	O
row	O
.	O
</s>
<s>
The	O
latter	O
,	O
as	O
well	O
as	O
"	O
rn	O
"	O
/	O
"	O
m	B-Language
"	O
/	O
"	O
rri	O
"	O
(	O
"	O
RN	O
"	O
/	O
"	O
M	B-Language
"	O
/	O
"	O
RRI	O
"	O
)	O
confusion	O
,	O
is	O
still	O
possible	O
for	O
a	O
human	O
eye	O
even	O
with	O
modern	O
advanced	O
computer	O
technology	O
.	O
</s>
<s>
ASCII	B-Protocol
has	O
several	O
characters	O
or	O
pairs	O
of	O
characters	O
that	O
look	O
alike	O
and	O
are	O
known	O
as	O
homographs	O
(	O
or	O
homoglyphs	O
)	O
.	O
</s>
<s>
Spoofing	O
attacks	O
based	O
on	O
these	O
similarities	O
are	O
known	O
as	O
homograph	B-General_Concept
spoofing	I-General_Concept
attacks	I-General_Concept
.	O
</s>
<s>
For	O
example	O
,	O
0	O
(	O
the	O
number	O
)	O
and	O
O	B-Language
(	O
the	O
letter	O
)	O
,	O
"	O
l	O
"	O
lowercase	O
L	O
,	O
and	O
"	O
I	O
"	O
uppercase	O
"	O
i	O
"	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
domain	O
"	O
rnicrosoft.com	O
 "	O
begins	O
with	O
"	O
r	O
"	O
and	O
"	O
n	B-Application
"	O
,	O
not	O
"	O
m	B-Language
"	O
.	O
</s>
<s>
In	O
certain	O
narrow-spaced	O
fonts	O
such	O
as	O
Tahoma	O
(	O
the	O
default	O
in	O
the	O
address	O
bar	O
in	O
Windows	B-Application
XP	I-Application
)	O
,	O
placing	O
a	O
c	B-Language
in	O
front	O
of	O
a	O
j	B-Language
,	O
l	O
or	O
i	O
will	O
produce	O
homoglyphs	O
such	O
as	O
cl	O
cj	O
ci	O
(	O
d	B-Application
g	B-Application
a	O
)	O
.	O
</s>
<s>
The	O
problem	O
arises	O
from	O
the	O
different	O
treatment	O
of	O
the	O
characters	O
in	O
the	O
user	O
's	O
mind	O
and	O
the	O
computer	O
's	O
programming	O
.	O
</s>
<s>
Thus	O
,	O
the	O
user	O
's	O
assumption	O
of	O
a	O
one-to-one	O
correspondence	O
between	O
the	O
visual	O
appearance	O
of	O
a	O
name	O
and	O
the	O
named	O
entity	O
breaks	O
down	O
.	O
</s>
<s>
Internationalized	B-Language
domain	I-Language
names	I-Language
provide	O
a	O
backward-compatible	O
way	O
for	O
domain	O
names	O
to	O
use	O
the	O
full	O
Unicode	O
character	O
set	O
,	O
and	O
this	O
standard	O
is	O
already	O
widely	O
supported	O
.	O
</s>
<s>
However	O
this	O
system	O
expanded	O
the	O
character	O
repertoire	O
from	O
a	O
few	O
dozen	O
characters	O
in	O
a	O
single	O
alphabet	O
to	O
many	O
thousands	O
of	O
characters	O
in	O
many	O
scripts	O
;	O
this	O
greatly	O
increased	O
the	O
scope	O
for	O
homograph	B-General_Concept
attacks	I-General_Concept
.	O
</s>
<s>
The	O
attacker	O
could	O
then	O
send	O
e-mail	O
messages	O
purporting	O
to	O
come	O
from	O
the	O
original	O
site	O
,	O
but	O
directing	O
people	O
to	O
the	O
bogus	O
site	O
.	O
</s>
<s>
In	O
December	O
2001	O
Evgeniy	O
Gabrilovich	O
and	O
Alex	O
Gontmakher	O
,	O
both	O
from	O
Technion	O
,	O
Israel	O
,	O
published	O
a	O
paper	O
titled	O
"	O
The	O
Homograph	B-General_Concept
Attack	I-General_Concept
"	O
,	O
which	O
described	O
an	O
attack	O
that	O
used	O
Unicode	O
URLs	O
to	O
spoof	O
a	O
website	O
URL	O
.	O
</s>
<s>
Web	O
browsers	O
supporting	O
IDNA	B-Language
appeared	O
to	O
direct	O
the	O
URL	O
http://www.pаypal.com/	O
,	O
in	O
which	O
the	O
first	O
a	O
character	O
is	O
replaced	O
by	O
a	O
Cyrillic	O
а	O
,	O
to	O
the	O
site	O
of	O
the	O
well	O
known	O
payment	O
site	O
PayPal	O
,	O
but	O
actually	O
led	O
to	O
a	O
spoofed	O
web	O
site	O
with	O
different	O
content	O
.	O
</s>
<s>
Popular	O
browsers	O
continued	O
to	O
have	O
problems	O
properly	O
displaying	O
international	B-Language
domain	I-Language
names	I-Language
through	O
April	O
2017	O
.	O
</s>
<s>
The	O
Cyrillic	O
letters	O
а	O
,	O
с	O
,	O
е	O
,	O
о	O
,	O
р	O
,	O
х	O
and	O
у	O
have	O
optical	O
counterparts	O
in	O
the	O
basic	O
Latin	O
alphabet	O
and	O
look	O
close	O
or	O
identical	O
to	O
a	O
,	O
c	B-Language
,	O
e	B-Language
,	O
o	B-Language
,	O
p	B-Language
,	O
x	B-Operating_System
and	O
y	O
.	O
Cyrillic	O
З	O
,	O
Ч	O
and	O
б	O
resemble	O
the	O
numerals	O
3	O
,	O
4	O
and	O
6	O
.	O
</s>
<s>
Italic	O
type	O
generates	O
more	O
homoglyphs	O
:	O
дтпи	O
or	O
дтпи	O
( дтпи	O
in	O
standard	O
type	O
)	O
,	O
resembling	O
dmnu	O
(	O
in	O
some	O
fonts	O
д	O
can	O
be	O
used	O
,	O
since	O
its	O
italic	O
form	O
resembles	O
a	O
lowercase	O
g	B-Application
;	O
however	O
,	O
in	O
most	O
mainstream	O
fonts	O
,	O
д	O
instead	O
resembles	O
a	O
partial	O
differential	O
sign	O
,	O
∂	O
)	O
.	O
</s>
<s>
Cyrillic	O
non-Russian	O
problematic	O
letters	O
are	O
і	O
and	O
i	O
,	O
ј	O
and	O
j	B-Language
,	O
ԛ	O
and	O
q	B-Algorithm
,	O
ѕ	O
and	O
s	B-Language
,	O
ԝ	O
and	O
w	B-Device
,	O
Ү	O
and	O
Y	O
,	O
while	O
Ғ	O
and	O
F	B-Language
,	O
Ԍ	O
and	O
G	B-Application
bear	O
some	O
resemblance	O
to	O
each	O
other	O
.	O
</s>
<s>
While	O
Komi	O
De	O
( ԁ	O
)	O
,	O
shha	O
( һ	O
)	O
,	O
palochka	O
( Ӏ	O
)	O
and	O
izhitsa	O
( ѵ	O
)	O
bear	O
strong	O
resemblance	O
to	O
Latin	O
d	B-Application
,	O
h	O
,	O
l	O
and	O
v	O
,	O
these	O
letters	O
are	O
either	O
rare	O
or	O
archaic	O
and	O
are	O
not	O
widely	O
supported	O
in	O
most	O
standard	O
fonts	O
(	O
they	O
are	O
not	O
included	O
in	O
the	O
WGL-4	O
)	O
.	O
</s>
<s>
This	O
list	O
increases	O
if	O
close	O
matches	O
are	O
also	O
allowed	O
(	O
such	O
as	O
Greek	O
εικηρτυωχγ	O
for	O
eiknptuwxy	O
)	O
.	O
</s>
<s>
The	O
Armenian	O
alphabet	O
can	O
also	O
contribute	O
critical	O
characters	O
:	O
several	O
Armenian	O
characters	O
like	O
օ	O
,	O
ո	O
,	O
ս	O
,	O
as	O
well	O
capital	O
Տ	O
and	O
Լ	O
are	O
often	O
completely	O
identical	O
to	O
Latin	O
characters	O
in	O
modern	O
fonts	O
,	O
and	O
symbols	O
which	O
similar	O
enough	O
to	O
pass	O
off	O
,	O
such	O
as	O
ցհոօզս	O
which	O
look	O
like	O
ghnoqu	O
,	O
յ	O
which	O
resembles	O
j	B-Language
(	O
albeit	O
dotless	O
)	O
,	O
and	O
ք	O
,	O
which	O
can	O
either	O
resemble	O
p	B-Language
or	O
f	B-Language
depending	O
on	O
the	O
font	O
;	O
ա	O
can	O
resemble	O
Cyrillic	O
ш	O
.	O
</s>
<s>
Furthermore	O
,	O
this	O
font	O
differentiates	O
Latin	O
g	B-Application
from	O
Armenian	O
ց	O
.	O
</s>
<s>
Only	O
three	O
letters	O
from	O
that	O
alphabet	O
can	O
reliably	O
be	O
used	O
:	O
samekh	O
( ס	O
)	O
,	O
which	O
sometimes	O
resembles	O
o	B-Language
,	O
vav	O
with	O
diacritic	O
( וֹ	O
)	O
,	O
which	O
resembles	O
an	O
i	O
,	O
and	O
heth	O
( ח	O
)	O
,	O
which	O
resembles	O
the	O
letter	O
n	B-Application
.	O
Less	O
accurate	O
approximants	O
for	O
some	O
other	O
alphanumerics	O
can	O
also	O
be	O
found	O
,	O
but	O
these	O
are	O
usually	O
only	O
accurate	O
enough	O
to	O
use	O
for	O
the	O
purposes	O
of	O
foreign	O
branding	O
and	O
not	O
for	O
substitution	O
.	O
</s>
<s>
ค	O
(	O
A	O
)	O
,	O
ท	O
(	O
n	B-Application
)	O
,	O
น	O
(	O
u	O
)	O
,	O
บ	O
(	O
U	O
)	O
,	O
ป	O
(	O
J	B-Language
)	O
,	O
พ	O
(	O
W	B-Device
)	O
,	O
ร	O
(	O
S	B-Language
)	O
,	O
and	O
ล	O
(	O
a	O
)	O
are	O
among	O
the	O
Thai	O
glyphs	O
that	O
can	O
closely	O
resemble	O
Latin	O
.	O
</s>
<s>
.hk	B-General_Concept
(	O
.香港	B-General_Concept
)	O
also	O
adopts	O
this	O
policy	O
.	O
</s>
<s>
In	O
most	O
top-level	O
domain	O
registries	O
,	O
wíkipedia.tld	O
(	O
xn--wkipedia-c2a.tld	O
)	O
and	O
wikipedia.tld	O
are	O
two	O
different	O
names	O
which	O
may	O
be	O
held	O
by	O
different	O
registrants	O
.	O
</s>
<s>
One	O
exception	O
is	O
.ca	B-General_Concept
,	O
where	O
reserving	O
the	O
plain-ASCII	O
version	O
of	O
the	O
domain	O
prevents	O
another	O
registrant	O
from	O
claiming	O
an	O
accented	O
version	O
of	O
the	O
same	O
name	O
.	O
</s>
<s>
In	O
general	O
,	O
ICANN	B-Application
prohibits	O
any	O
domain	O
with	O
these	O
characters	O
from	O
being	O
registered	O
,	O
regardless	O
of	O
TLD	O
.	O
</s>
<s>
In	O
2011	O
,	O
an	O
unknown	O
source	O
(	O
registering	O
under	O
the	O
name	O
"	O
Completely	O
Anonymous	O
"	O
)	O
registered	O
a	O
domain	O
name	O
homographic	O
to	O
television	O
station	O
KBOI-TV	O
'	O
s	B-Language
to	O
create	O
a	O
fake	O
news	O
website	O
.	O
</s>
<s>
The	O
sole	O
purpose	O
of	O
the	O
site	O
was	O
to	O
spread	O
an	O
April	O
Fool	O
's	O
Day	O
joke	O
regarding	O
the	O
Governor	O
of	O
Idaho	O
issuing	O
a	O
supposed	O
ban	O
on	O
the	O
sale	O
of	O
music	O
by	O
Justin	O
Bieber	O
.	O
</s>
<s>
In	O
September	O
2017	O
,	O
security	O
researcher	O
Ankit	O
Anubhav	O
discovered	O
an	O
IDN	B-General_Concept
homograph	I-General_Concept
attack	I-General_Concept
where	O
the	O
attackers	O
registered	O
adoḅe.com	O
to	O
deliver	O
the	O
Betabot	O
trojan	O
.	O
</s>
<s>
The	O
simplest	O
defense	O
is	O
for	O
web	O
browsers	O
not	O
to	O
support	O
IDNA	B-Language
or	O
other	O
similar	O
mechanisms	O
,	O
or	O
for	O
users	O
to	O
turn	O
off	O
whatever	O
support	O
their	O
browsers	O
have	O
.	O
</s>
<s>
That	O
could	O
mean	O
blocking	O
access	O
to	O
IDNA	B-Language
sites	O
,	O
but	O
generally	O
browsers	O
permit	O
access	O
and	O
just	O
display	O
IDNs	B-Language
in	O
Punycode	B-General_Concept
.	O
</s>
<s>
Either	O
way	O
,	O
this	O
amounts	O
to	O
abandoning	O
non-ASCII	O
domain	O
names	O
.	O
</s>
<s>
Google	B-Application
Chrome	I-Application
versions	O
51	O
and	O
later	O
use	O
an	O
algorithm	O
similar	O
to	O
the	O
one	O
used	O
by	O
Firefox	B-Application
.	O
</s>
<s>
Previous	O
versions	O
display	O
an	O
IDN	O
only	O
if	O
all	O
of	O
its	O
characters	O
belong	O
to	O
one	O
(	O
and	O
only	O
one	O
)	O
of	O
the	O
user	O
's	O
preferred	O
languages	O
.	O
</s>
<s>
Chromium	B-Language
and	O
Chromium-based	O
browsers	O
such	O
as	O
Microsoft	O
Edge	O
(	O
since	O
2019	O
)	O
and	O
Opera	B-Application
also	O
use	O
the	O
same	O
algorithm	O
.	O
</s>
<s>
Safari	B-Application
's	I-Application
approach	O
is	O
to	O
render	O
problematic	O
character	O
sets	O
as	O
Punycode	B-General_Concept
.	O
</s>
<s>
This	O
can	O
be	O
changed	O
by	O
altering	O
the	O
settings	O
in	O
Mac	B-Application
OS	I-Application
X	I-Application
's	O
system	O
files	O
.	O
</s>
<s>
Mozilla	B-Application
Firefox	I-Application
versions	O
22	O
and	O
later	O
display	O
IDNs	B-Language
if	O
either	O
the	O
TLD	O
prevents	O
homograph	B-General_Concept
attacks	I-General_Concept
by	O
restricting	O
which	O
characters	O
can	O
be	O
used	O
in	O
domain	O
names	O
or	O
labels	O
do	O
not	O
mix	O
scripts	O
for	O
different	O
languages	O
.	O
</s>
<s>
Otherwise	O
IDNs	B-Language
are	O
displayed	O
in	O
Punycode	B-General_Concept
.	O
</s>
<s>
Internet	B-Application
Explorer	I-Application
versions	O
7	O
and	O
later	O
allow	O
IDNs	B-Language
except	O
for	O
labels	O
that	O
mix	O
scripts	O
for	O
different	O
languages	O
.	O
</s>
<s>
Labels	O
that	O
mix	O
scripts	O
are	O
displayed	O
in	O
Punycode	B-General_Concept
.	O
</s>
<s>
There	O
are	O
exceptions	O
to	O
locales	O
where	O
ASCII	B-Protocol
characters	I-Protocol
are	O
commonly	O
mixed	O
with	O
localized	O
scripts	O
.	O
</s>
<s>
Internet	B-Application
Explorer	I-Application
7	O
was	O
capable	O
of	O
using	O
IDNs	B-Language
,	O
but	O
it	O
imposes	O
restrictions	O
on	O
displaying	O
non-ASCII	O
domain	O
names	O
based	O
on	O
a	O
user-defined	O
list	O
of	O
allowed	O
languages	O
and	O
provides	O
an	O
anti-phishing	O
filter	O
that	O
checks	O
suspicious	O
Web	O
sites	O
against	O
a	O
remote	O
database	O
of	O
known	O
phishing	O
sites	O
.	O
</s>
<s>
Old	O
Microsoft	O
Edge	O
converts	O
all	O
Unicode	O
into	O
Punycode	B-General_Concept
.	O
</s>
<s>
As	O
an	O
additional	O
defense	O
,	O
Internet	B-Application
Explorer	I-Application
7	O
,	O
Firefox	B-Application
2.0	O
and	O
above	O
,	O
and	O
Opera	B-Application
9.10	O
include	O
phishing	O
filters	O
that	O
attempt	O
to	O
alert	O
users	O
when	O
they	O
visit	O
malicious	O
websites	O
.	O
</s>
<s>
As	O
of	O
April	O
2017	O
,	O
several	O
browsers	O
(	O
including	O
Chrome	B-Application
,	O
Firefox	B-Application
and	O
Opera	B-Application
)	O
were	O
displaying	O
IDNs	B-Language
consisting	O
purely	O
of	O
Cyrillic	O
characters	O
normally	O
(	O
not	O
as	O
punycode	B-General_Concept
)	O
,	O
allowing	O
spoofing	O
attacks	O
.	O
</s>
<s>
Chrome	B-Application
tightened	O
IDN	O
restrictions	O
in	O
version	O
59	O
to	O
prevent	O
this	O
attack	O
.	O
</s>
<s>
Browser	B-Protocol
extensions	I-Protocol
like	O
No	O
Homo-Graphs	O
are	O
available	O
for	O
Google	B-Application
Chrome	I-Application
and	O
Firefox	B-Application
that	O
check	O
whether	O
the	O
user	O
is	O
visiting	O
a	O
website	O
which	O
is	O
a	O
homograph	O
of	O
another	O
domain	O
from	O
a	O
user-defined	O
list	O
.	O
</s>
<s>
Homographic	O
URLs	O
that	O
house	O
malicious	O
software	O
can	O
still	O
be	O
distributed	O
,	O
without	O
being	O
displayed	O
as	O
Punycode	B-General_Concept
,	O
through	O
e-mail	O
,	O
social	O
networking	O
or	O
other	O
Web	O
sites	O
without	O
being	O
detected	O
until	O
the	O
user	O
actually	O
clicks	O
the	O
link	O
.	O
</s>
<s>
While	O
the	O
fake	O
link	O
will	O
show	O
in	O
Punycode	B-General_Concept
when	O
it	O
is	O
clicked	O
,	O
by	O
this	O
point	O
the	O
page	O
has	O
already	O
begun	O
loading	O
into	O
the	O
browser	O
and	O
the	O
malicious	O
software	O
may	O
have	O
already	O
been	O
downloaded	O
onto	O
the	O
computer	O
.	O
</s>
<s>
ICANN	B-Application
has	O
implemented	O
a	O
policy	O
prohibiting	O
any	O
potential	O
internationalized	O
TLD	O
from	O
choosing	O
letters	O
that	O
could	O
resemble	O
an	O
existing	O
Latin	O
TLD	O
and	O
thus	O
be	O
used	O
for	O
homograph	B-General_Concept
attacks	I-General_Concept
.	O
</s>
<s>
Proposed	O
IDN	O
TLDs	O
.бг	B-Language
(	O
Bulgaria	O
)	O
,	O
.укр	O
(	O
Ukraine	O
)	O
and	O
.ελ	O
(	O
Greece	O
)	O
have	O
been	O
rejected	O
or	O
stalled	O
because	O
of	O
their	O
perceived	O
resemblance	O
to	O
Latin	O
letters	O
.	O
</s>
<s>
All	O
three	O
(	O
and	O
Serbian	O
.срб	B-General_Concept
and	O
Mongolian	O
.мон	O
)	O
have	O
later	O
been	O
accepted	O
.	O
</s>
<s>
Three-letter	O
TLD	O
are	O
considered	O
safer	O
than	O
two-letter	O
TLD	O
,	O
since	O
they	O
are	O
harder	O
to	O
match	O
to	O
normal	O
Latin	O
ISO-3166	O
country	O
domains	O
;	O
although	O
the	O
potential	O
to	O
match	O
new	O
generic	O
domains	O
remains	O
,	O
such	O
generic	O
domains	O
are	O
far	O
more	O
expensive	O
than	O
registering	O
a	O
second	O
-	O
or	O
third-level	O
domain	O
address	O
,	O
making	O
it	O
cost-prohibitive	O
to	O
try	O
to	O
register	O
a	O
homoglyphic	O
TLD	O
for	O
the	O
sole	O
purpose	O
of	O
making	O
fraudulent	O
domains	O
(	O
which	O
itself	O
would	O
draw	O
ICANN	B-Application
scrutiny	O
)	O
.	O
</s>
<s>
The	O
Russian	O
registry	O
operator	O
Coordination	B-Protocol
Center	I-Protocol
for	I-Protocol
TLD	I-Protocol
RU	I-Protocol
only	O
accepts	O
Cyrillic	O
names	O
for	O
the	O
top-level	O
domain	O
.рф	O
,	O
forbidding	O
a	O
mix	O
with	O
Latin	O
or	O
Greek	O
characters	O
.	O
</s>
