<s>
A	O
Machine	B-Application
Identification	I-Application
Code	I-Application
(	O
MIC	O
)	O
,	O
also	O
known	O
as	O
printer	B-Application
steganography	I-Application
,	O
yellow	B-Application
dots	I-Application
,	O
tracking	B-Application
dots	I-Application
or	O
secret	O
dots	O
,	O
is	O
a	O
digital	O
watermark	O
which	O
certain	O
color	O
laser	O
printers	O
and	O
copiers	O
leave	O
on	O
every	O
printed	O
page	O
,	O
allowing	O
identification	O
of	O
the	O
device	O
which	O
was	O
used	O
to	O
print	O
a	O
document	O
and	O
giving	O
clues	O
to	O
the	O
originator	O
.	O
</s>
<s>
In	O
2018	O
,	O
scientists	O
developed	O
privacy	B-Application
software	I-Application
to	O
anonymize	O
prints	O
in	O
order	O
to	O
support	O
whistleblowers	O
publishing	O
their	O
work	O
.	O
</s>
<s>
Xerox	O
developed	O
the	O
machine	B-Application
identification	I-Application
code	I-Application
"	O
to	O
assuage	O
fears	O
that	O
their	O
color	O
copiers	O
could	O
be	O
used	O
to	O
counterfeit	O
bills	O
"	O
and	O
received	O
U.S.	O
Patent	O
No	O
5515451	O
describing	O
the	O
use	O
of	O
the	O
yellow	B-Application
dots	I-Application
to	O
identify	O
the	O
source	O
of	O
a	O
copied	O
or	O
printed	O
document	O
.	O
</s>
<s>
In	O
November	O
2004	O
,	O
PC	O
World	O
reported	O
the	O
machine	B-Application
identification	I-Application
code	I-Application
had	O
been	O
used	O
for	O
decades	O
in	O
some	O
printers	O
,	O
allowing	O
law	O
enforcement	O
to	O
identify	O
and	O
track	O
counterfeiters	O
.	O
</s>
<s>
The	O
pattern	O
consists	O
of	O
a	O
dot-matrix	O
spread	O
of	O
yellow	B-Application
dots	I-Application
,	O
which	O
can	O
barely	O
be	O
seen	O
with	O
the	O
naked	O
eye	O
.	O
</s>
<s>
Some	O
printers	O
arrange	O
yellow	B-Application
dots	I-Application
in	O
seemingly	O
random	O
point	O
clouds	O
.	O
</s>
<s>
The	O
Machine	B-Application
Identification	I-Application
Code	I-Application
can	O
be	O
made	O
visible	O
by	O
printing	O
or	O
copying	O
a	O
page	O
and	O
subsequently	O
scanning	O
a	O
small	O
section	O
with	O
a	O
high-resolution	O
scanner	B-Application
.	O
</s>
<s>
Under	O
UV-light	O
the	O
yellow	B-Application
dots	I-Application
are	O
clearly	O
recognizable	O
.	O
</s>
<s>
Both	O
journalists	O
and	O
security	O
experts	O
have	O
suggested	O
that	O
The	O
Intercept	O
handling	O
of	O
the	O
leaks	O
by	O
whistleblower	O
Reality	O
Winner	O
,	O
which	O
included	O
publishing	O
secret	O
NSA	O
documents	O
unredacted	O
and	O
including	O
the	O
printer	B-Application
tracking	I-Application
dots	I-Application
,	O
was	O
used	O
to	O
identify	O
Winner	O
as	O
the	O
leaker	O
,	O
leading	O
to	O
her	O
arrest	O
and	O
conviction	O
.	O
</s>
<s>
In	O
2005	O
the	O
Electronic	O
Frontier	O
Foundation	O
(	O
EFF	O
)	O
sought	O
a	O
decoding	O
method	O
and	O
made	O
available	O
a	O
Python	B-Language
script	I-Language
for	O
analysis	O
.	O
</s>
<s>
The	O
anonymization	O
works	O
by	O
printing	O
additional	O
yellow	B-Application
dots	I-Application
on	O
top	O
of	O
the	O
Machine	B-Application
Identification	I-Application
Code	I-Application
.	O
</s>
<s>
Other	O
methods	O
of	O
identification	O
are	O
not	O
as	O
easily	O
recognizable	O
as	O
yellow	B-Application
dots	I-Application
.	O
</s>
