<s>
In	O
cryptography	O
,	O
M6	B-Algorithm
is	O
a	O
block	O
cipher	O
proposed	O
by	O
Hitachi	O
in	O
1997	O
for	O
use	O
in	O
the	O
IEEE	B-Protocol
1394	I-Protocol
FireWire	I-Protocol
standard	O
.	O
</s>
<s>
The	O
design	O
allows	O
some	O
freedom	O
in	O
choosing	O
a	O
few	O
of	O
the	O
cipher	O
's	O
operations	O
,	O
so	O
M6	B-Algorithm
is	O
considered	O
a	O
family	O
of	O
ciphers	O
.	O
</s>
<s>
Due	O
to	O
export	O
controls	O
,	O
M6	B-Algorithm
has	O
not	O
been	O
fully	O
published	O
;	O
nevertheless	O
,	O
a	O
partial	O
description	O
of	O
the	O
algorithm	O
based	O
on	O
a	O
draft	O
standard	O
is	O
given	O
by	O
Kelsey	O
,	O
et	O
al	O
.	O
</s>
<s>
The	O
key	B-Algorithm
schedule	I-Algorithm
is	O
very	O
simple	O
,	O
producing	O
two	O
32-bit	O
subkeys	O
:	O
the	O
high	O
32	O
bits	O
of	O
the	O
key	O
,	O
and	O
the	O
sum	O
mod	O
232	O
of	O
this	O
and	O
the	O
low	O
32	O
bits	O
.	O
</s>
<s>
Due	O
to	O
its	O
simple	O
key	B-Algorithm
schedule	I-Algorithm
,	O
M6	B-Algorithm
is	O
also	O
vulnerable	O
to	O
a	O
slide	O
attack	O
,	O
which	O
requires	O
more	O
known	O
plaintext	O
but	O
less	O
computation	O
.	O
</s>
