<s>
In	O
cryptography	O
,	O
MUGI	B-Algorithm
is	O
a	O
pseudorandom	B-Algorithm
number	I-Algorithm
generator	I-Algorithm
(	O
PRNG	O
)	O
designed	O
for	O
use	O
as	O
a	O
stream	B-Algorithm
cipher	I-Algorithm
.	O
</s>
<s>
MUGI	B-Algorithm
takes	O
a	O
128-bit	O
secret	O
key	O
and	O
a	O
128-bit	O
initial	B-Algorithm
vector	I-Algorithm
(	O
IV	O
)	O
.	O
</s>
<s>
After	O
a	O
key	O
-	O
and	O
IV	O
-	O
setup	O
process	O
,	O
MUGI	B-Algorithm
outputs	O
64-bit	O
output	O
strings	O
based	O
on	O
the	O
internal	O
state	O
,	O
while	O
updating	O
the	O
internal	O
state	O
after	O
each	O
output	O
block	O
.	O
</s>
<s>
MUGI	B-Algorithm
has	O
a	O
1216-bit	O
internal	O
state	O
;	O
there	O
are	O
three	O
64-bit	O
registers	O
(	O
the	O
"	O
state	O
"	O
)	O
and	O
16	O
64-bit	O
registers	O
(	O
the	O
"	O
buffer	O
"	O
)	O
.	O
</s>
<s>
MUGI	B-Algorithm
uses	O
the	O
non-linear	O
S-box	B-Algorithm
that	O
was	O
originally	O
defined	O
in	O
Advanced	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
(	O
AES	B-Algorithm
)	O
.	O
</s>
<s>
A	O
part	O
of	O
the	O
linear	O
transformation	O
also	O
reuses	O
the	O
MDS	B-General_Concept
matrix	I-General_Concept
of	O
AES	B-Algorithm
.	O
</s>
<s>
The	O
basic	O
design	O
is	O
influenced	O
by	O
that	O
of	O
Panama	B-Algorithm
.	O
</s>
<s>
As	O
of	O
September	O
2006	O
,	O
there	O
are	O
no	O
known	O
attacks	O
against	O
MUGI	B-Algorithm
that	O
are	O
faster	O
than	O
serial	O
brute-force	O
of	O
the	O
key	O
space	O
or	O
of	O
the	O
internal	O
state	O
.	O
</s>
<s>
In	O
the	O
paper	O
,	O
"	O
A	O
weakness	O
of	O
the	O
linear	O
part	O
of	O
stream	B-Algorithm
cipher	I-Algorithm
MUGI	B-Algorithm
"	O
,	O
by	O
Golic	O
Jovan	O
Dj	O
,	O
Roy	O
Bimal	O
and	O
Meier	O
Willi	O
,	O
the	O
abstract	O
claims	O
:	O
"	O
The	O
linearly	O
updated	O
component	O
of	O
the	O
stream	B-Algorithm
cipher	I-Algorithm
MUGI	B-Algorithm
,	O
called	O
the	O
buffer	O
,	O
is	O
analyzed	O
theoretically	O
by	O
using	O
the	O
generating	O
function	O
method	O
.	O
</s>
<s>
It	O
is	O
then	O
shown	O
how	O
this	O
weakness	O
can	O
in	O
principle	O
be	O
used	O
to	O
facilitate	O
the	O
linear	O
cryptanalysis	O
of	O
MUGI	B-Algorithm
with	O
two	O
main	O
objectives	O
:	O
to	O
reconstruct	O
the	O
secret	O
key	O
and	O
to	O
find	O
linear	O
statistical	O
distinguishers.	O
"	O
</s>
<s>
In	O
the	O
paper	O
,	O
"	O
Analysis	O
of	O
the	O
Non-linear	O
Part	O
of	O
Mugi	B-Algorithm
"	O
by	O
Alex	O
Biryukov	O
and	O
Adi	O
Shamir	O
,	O
the	O
abstract	O
claims	O
:	O
"	O
This	O
paper	O
presents	O
the	O
results	O
of	O
a	O
preliminary	O
analysis	O
of	O
the	O
stream	B-Algorithm
cipher	I-Algorithm
Mugi	B-Algorithm
.	O
</s>
<s>
While	O
we	O
can	O
not	O
break	O
the	O
full	O
Mugi	B-Algorithm
design	O
,	O
we	O
show	O
that	O
it	O
is	O
extremely	O
sensitive	O
to	O
small	O
variations	O
.	O
</s>
