<s>
Nagravision	B-Device
(	O
or	O
Nagra	O
Kudelski	O
or	O
simply	O
Nagra	O
)	O
is	O
a	O
company	O
of	O
the	O
Kudelski	O
Group	O
that	O
develops	O
conditional	B-Architecture
access	I-Architecture
systems	I-Architecture
for	O
digital	O
cable	O
and	O
satellite	O
television	O
.	O
</s>
<s>
The	O
name	O
is	O
also	O
used	O
for	O
their	O
main	O
products	O
,	O
the	O
Nagravision	B-Device
encryption	O
systems	O
.	O
</s>
<s>
An	O
analog	O
Nagravision	B-Device
system	O
(	O
Syster	O
)	O
for	O
scrambling	O
analog	O
satellite	O
television	O
programs	O
was	O
used	O
in	O
the	O
1990s	O
.	O
</s>
<s>
In	O
this	O
line-shuffling	O
system	O
,	O
bottom	O
32	O
lines	O
of	O
the	O
PAL	O
TV	O
signal	O
are	O
shifted	O
in	O
time	O
by	O
one	O
video	O
field	O
,	O
and	O
read	O
out	O
in	O
permuted	O
order	O
under	O
the	O
control	O
of	O
a	O
pseudorandom	B-Algorithm
number	I-Algorithm
generator	I-Algorithm
.	O
</s>
<s>
A	O
smartcard	O
security	O
microcontroller	B-Architecture
(	O
in	O
a	O
key-shaped	O
package	O
)	O
decrypts	O
data	O
that	O
is	O
transmitted	O
during	O
the	O
blanking	O
intervals	O
of	O
the	O
TV	O
signal	O
mixed	O
with	O
teletext	O
and	O
extracts	O
the	O
random	B-Algorithm
seed	I-Algorithm
value	O
which	O
contains	O
present	O
line	O
combination	O
needed	O
for	O
reverting	O
the	O
picture	O
back	O
.	O
</s>
<s>
4	O
currently	O
used	O
versions	O
of	O
Nagravision	B-Device
are	O
in	O
common	O
use	O
for	O
digital	O
satellite	O
television	O
,	O
known	O
as	O
Nagravision	B-Device
,	O
Nagravision	B-Device
Cardmagedon	O
,	O
Nagravision	B-Device
Aladin	O
and	O
Nagravision	B-Device
Merlin	O
.	O
</s>
<s>
Nagravision	B-Device
Cardmagedon	O
and	O
Aladin	O
are	O
often	O
confused	O
with	O
each	O
other	O
and	O
used	O
under	O
the	O
term	O
"	O
Nagravision	B-Device
2	O
"	O
which	O
technically	O
does	O
not	O
exist	O
.	O
</s>
<s>
Nagravision	B-Device
Cardmagedon	O
is	O
,	O
however	O
,	O
a	O
complicated	O
combination	O
of	O
Nagravision	B-Device
Aladin	O
and	O
Mediaguard	O
SECA	O
2	O
encryption	O
.	O
</s>
<s>
Nagravision	B-Device
Merlin	O
is	O
also	O
known	O
as	O
Nagravision	B-Device
3	O
.	O
</s>
<s>
The	O
decryption	O
unit	O
is	O
either	O
integrated	O
into	O
a	O
receiver	O
,	O
available	O
as	O
a	O
conditional-access	B-Device
module	I-Device
(	O
CAM	O
)	O
,	O
or	O
as	O
one	O
of	O
many	O
encryption	O
schemes	O
supported	O
on	O
a	O
CAM	O
emulator	B-Application
.	O
</s>
<s>
Nagravision	B-Device
has	O
been	O
adopted	O
all	O
over	O
the	O
world	O
as	O
a	O
conditional	B-Architecture
access	I-Architecture
system	I-Architecture
,	O
with	O
providers	O
:	O
</s>
