<s>
MULTI2	B-Algorithm
is	O
a	O
block	O
cipher	O
,	O
developed	O
by	O
Hitachi	O
in	O
1988	O
.	O
</s>
<s>
Designed	O
for	O
general-purpose	O
cryptography	O
,	O
its	O
current	O
use	O
is	O
encryption	O
of	O
high-definition	B-Device
television	I-Device
broadcasts	B-Operating_System
in	O
Japan	O
.	O
</s>
<s>
MULTI2	B-Algorithm
is	O
a	O
symmetric	B-Algorithm
key	I-Algorithm
algorithm	I-Algorithm
with	O
variable	O
number	O
of	O
rounds	O
.	O
</s>
<s>
A	O
256-bit	O
implementation-dependent	O
substitution	B-Algorithm
box	I-Algorithm
constant	O
is	O
used	O
during	O
key	B-Algorithm
schedule	I-Algorithm
.	O
</s>
<s>
There	O
are	O
a	O
large	O
class	O
of	O
equivalent	O
keys	O
in	O
the	O
Multi2	B-Algorithm
block	O
cipher	O
.	O
</s>
<s>
The	O
largest	O
class	O
(	O
so	O
far	O
found	O
)	O
stems	O
from	O
the	O
fact	O
that	O
the	O
Pi3	O
round	O
function	O
in	O
the	O
key	B-Algorithm
schedule	I-Algorithm
is	O
not	O
bijective	B-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
with	O
the	O
following	O
40-byte	O
input	O
key	O
to	O
the	O
key	B-Algorithm
schedule	I-Algorithm
:	O
</s>
<s>
In	O
this	O
case	O
there	O
are	O
15	O
different	O
keys	O
which	O
will	O
schedule	O
to	O
the	O
same	O
8	O
32-bit	O
round	B-Algorithm
keys	I-Algorithm
for	O
the	O
ciphers	O
bulk	O
encryption	O
path	O
.	O
</s>
<s>
Where	O
ROL	O
means	O
rotate	O
left	O
by	O
y	O
bits	O
,	O
is	O
not	O
bijective	B-Algorithm
for	O
any	O
value	O
of	O
y	O
.	O
</s>
