<s>
A	O
conditional	B-Device
access	I-Device
module	I-Device
(	O
CAM	B-Data_Structure
)	O
is	O
an	O
electronic	O
device	O
,	O
usually	O
incorporating	O
a	O
slot	O
for	O
a	O
smart	O
card	O
,	O
which	O
equips	O
an	O
integrated	B-Device
digital	I-Device
television	I-Device
or	O
set-top	O
box	O
with	O
the	O
appropriate	O
hardware	O
facility	O
to	O
view	O
conditional	B-Architecture
access	I-Architecture
content	O
that	O
has	O
been	O
encrypted	O
using	O
a	O
conditional	B-Architecture
access	I-Architecture
system	I-Architecture
.	O
</s>
<s>
They	O
are	O
normally	O
used	O
with	O
direct-broadcast	O
satellite	O
(	O
DBS	O
)	O
services	O
,	O
although	O
digital	B-Application
terrestrial	I-Application
pay	O
TV	O
suppliers	O
also	O
use	O
CAMs	B-Data_Structure
.	O
</s>
<s>
PC	B-Architecture
Card	I-Architecture
form	O
factor	O
is	O
used	O
as	O
the	O
Common	B-Device
Interface	I-Device
form	O
of	O
Conditional	B-Device
Access	I-Device
Modules	I-Device
for	O
DVB	B-Application
broadcasts	O
.	O
</s>
<s>
Major	O
CAM	B-Data_Structure
manufacturers	O
include	O
:	O
Neotion	O
,	O
SmarDTV	O
and	O
SMIT	O
.	O
</s>
<s>
Some	O
encryption	O
systems	O
for	O
which	O
CAMs	B-Data_Structure
are	O
available	O
are	O
Logiways	O
,	O
Nagravision	B-Device
,	O
Viaccess	B-Device
,	O
Mediaguard	B-Device
,	O
Irdeto	O
,	O
KeyFly	B-Device
,	O
Verimatrix	O
,	O
Cryptoworks	B-Device
,	O
Mascom	O
,	O
Safeview	O
,	O
Diablo	O
CAM	B-Data_Structure
and	O
Conax	B-Device
.	O
</s>
<s>
NDS	B-Device
VideoGuard	B-Device
encryption	O
,	O
the	O
preferred	O
choice	O
of	O
Sky	O
Digital	O
can	O
only	O
be	O
externally	O
emulated	O
by	O
a	O
Dragon	O
brand	O
CAM	B-Data_Structure
.	O
</s>
<s>
The	O
NDS	B-Device
CAM	B-Data_Structure
that	O
the	O
Sky	O
viewing	O
card	O
ordinarily	O
uses	O
is	O
built	O
into	O
the	O
Sky	O
Digibox	O
and	O
thus	O
not	O
visible	O
.	O
</s>
<s>
Dragon	O
and	O
Matrix	O
,	O
two	O
popular	O
cams	B-Data_Structure
with	O
satellite	O
television	O
enthusiasts	O
are	O
multicrypt	O
meaning	O
each	O
is	O
capable	O
of	O
handling	O
more	O
than	O
one	O
encryption	O
system	O
.	O
</s>
<s>
Matrix	O
CAMs	B-Data_Structure
can	O
be	O
upgraded	O
via	O
the	O
PC	B-Architecture
Card	I-Architecture
port	O
in	O
a	O
laptop	B-Device
personal	O
computer	O
whereas	O
a	O
Dragon	O
cam	B-Data_Structure
update	O
is	O
done	O
via	O
separate	O
programmer	O
hardware	O
.	O
</s>
<s>
The	O
primary	O
purpose	O
of	O
the	O
CAM	B-Data_Structure
is	O
to	O
derive	O
control	O
words	O
,	O
which	O
are	O
short-term	O
decryption	O
keys	O
for	O
video	O
.	O
</s>
<s>
The	O
effectiveness	O
of	O
a	O
CAM	B-Data_Structure
depends	O
on	O
the	O
tamper	O
resistance	O
of	O
the	O
hardware	O
;	O
if	O
the	O
hardware	O
is	O
broken	O
,	O
the	O
functionality	O
of	O
the	O
CAM	B-Data_Structure
can	O
be	O
emulated	O
,	O
enabling	O
the	O
content	O
to	O
be	O
decrypted	O
by	O
non-subscribers	O
.	O
</s>
<s>
CAMs	B-Data_Structure
are	O
normally	O
removable	O
so	O
that	O
they	O
can	O
be	O
replaced	O
after	O
the	O
hardware	O
security	O
is	O
breached	O
.	O
</s>
<s>
Replacement	O
of	O
the	O
CAMs	B-Data_Structure
in	O
a	O
system	O
is	O
called	O
a	O
card	O
swap-out	O
.	O
</s>
<s>
CAM	B-Data_Structure
Modules	O
come	O
in	O
two	O
types	O
:	O
standard	O
,	O
intended	O
for	O
a	O
single	O
TV	O
consumer	O
,	O
and	O
professional	O
,	O
made	O
for	O
an	O
array	O
of	O
televisions	O
connected	O
to	O
a	O
rack	O
of	O
CAMs	B-Data_Structure
,	O
like	O
in	O
a	O
hospital	O
or	O
a	O
hotel	O
.	O
</s>
<s>
The	O
standard	O
format	O
for	O
a	O
CAM	B-Data_Structure
is	O
a	O
PC	B-Architecture
card	I-Architecture
which	O
takes	O
a	O
smart	O
card	O
to	O
authenticate	O
,	O
although	O
CAMs	B-Data_Structure
with	O
the	O
'	O
smart	O
card	O
 '	O
burnt	O
into	O
memory	O
,	O
known	O
as	O
Cardless	O
CAM	B-Data_Structure
,	O
can	O
be	O
found	O
.	O
</s>
<s>
With	O
the	O
CI+	B-Device
2.0	O
certification	O
came	O
a	O
new	O
USB	B-Device
dongle	I-Device
form	O
factor	O
.	O
</s>
<s>
In	O
addition	O
,	O
CAM	B-Data_Structure
emulators	O
exist	O
for	O
many	O
systems	O
,	O
either	O
providing	O
an	O
interface	O
to	O
allow	O
the	O
use	O
of	O
more	O
than	O
one	O
type	O
of	O
card	O
,	O
or	O
a	O
card	O
not	O
designed	O
for	O
that	O
receiver	O
.	O
</s>
