<s>
In	O
cryptography	O
,	O
N-hash	B-Algorithm
is	O
a	O
cryptographic	B-Algorithm
hash	I-Algorithm
function	I-Algorithm
based	O
on	O
the	O
FEAL	B-Algorithm
round	O
function	O
,	O
and	O
is	O
now	O
considered	O
insecure	O
.	O
</s>
<s>
N-hash	B-Algorithm
has	O
a	O
128-bit	O
hash	B-Algorithm
size	O
.	O
</s>
<s>
A	O
message	O
is	O
divided	O
into	O
128-bit	O
blocks	O
,	O
and	O
each	O
block	O
is	O
combined	O
with	O
the	O
hash	B-Algorithm
value	O
computed	O
so	O
far	O
using	O
the	O
g	O
compression	B-Algorithm
function	I-Algorithm
.	O
</s>
<s>
g	O
contains	O
eight	O
rounds	O
,	O
each	O
of	O
which	O
uses	O
an	O
F	O
function	O
,	O
similar	O
to	O
the	O
one	O
used	O
by	O
FEAL	B-Algorithm
.	O
</s>
<s>
Eli	O
Biham	O
and	O
Adi	O
Shamir	O
(	O
1991	O
)	O
applied	O
the	O
technique	O
of	O
differential	O
cryptanalysis	O
to	O
N-hash	B-Algorithm
,	O
and	O
showed	O
that	O
collisions	O
could	O
be	O
generated	O
faster	O
than	O
by	O
a	O
birthday	O
attack	O
for	O
N-hash	B-Algorithm
variants	O
with	O
even	O
up	O
to	O
12	O
rounds	O
.	O
</s>
