<s>
FORK-256	B-Algorithm
is	O
a	O
hash	B-Error_Name
algorithm	I-Error_Name
designed	O
in	O
response	O
to	O
security	O
issues	O
discovered	O
in	O
the	O
earlier	O
SHA-1	B-Algorithm
and	O
MD5	B-Algorithm
algorithms	O
.	O
</s>
<s>
In	O
2005	O
,	O
Xiaoyun	O
Wang	O
announced	O
an	O
order	O
-	O
collision	B-Algorithm
attack	I-Algorithm
on	O
the	O
government	O
's	O
hash	B-Error_Name
standard	O
SHA-1	B-Algorithm
.	O
</s>
<s>
The	O
National	O
Institute	O
of	O
Standards	O
and	O
Technology	O
(	O
NIST	O
)	O
,	O
the	O
body	O
responsible	O
for	O
setting	O
cryptographic	O
standards	O
in	O
the	O
United	O
States	O
,	O
concluded	O
this	O
was	O
a	O
practical	O
attack	O
(	O
as	O
previous	O
estimates	O
were	O
order	O
-	O
)	O
and	O
began	O
encouraging	O
additional	O
research	O
into	O
hash	B-Error_Name
functions	I-Error_Name
and	O
their	O
weaknesses	O
.	O
</s>
<s>
As	O
part	O
of	O
this	O
effort	O
,	O
NIST	O
hosted	O
two	O
workshops	O
where	O
potential	O
new	O
algorithms	O
,	O
including	O
FORK-256	B-Algorithm
,	O
were	O
introduced	O
and	O
discussed	O
.	O
</s>
<s>
Rather	O
than	O
immediately	O
select	O
any	O
of	O
these	O
algorithms	O
,	O
NIST	O
conducted	O
a	O
public	O
competition	O
from	O
20072012	O
which	O
ultimately	O
resulted	O
in	O
the	O
Keccak	B-Algorithm
algorithm	O
being	O
selected	O
for	O
use	O
as	O
the	O
SHA-3	B-Algorithm
standard	O
.	O
</s>
<s>
FORK-256	B-Algorithm
was	O
introduced	O
at	O
the	O
2005	O
NIST	O
Hash	B-Error_Name
workshop	O
and	O
published	O
the	O
following	O
year	O
.	O
</s>
<s>
FORK-256	B-Algorithm
uses	O
512-bit	O
blocks	O
and	O
implements	O
preset	O
constants	O
that	O
change	O
after	O
each	O
repetition	O
.	O
</s>
<s>
(	O
2006	O
)	O
discovered	O
a	O
collision	B-Algorithm
attack	I-Algorithm
with	O
complexity	O
of	O
.	O
</s>
<s>
In	O
response	O
to	O
these	O
attacks	O
,	O
Hong	O
and	O
his	O
team	O
proposed	O
an	O
improved	O
version	O
of	O
FORK-256	B-Algorithm
.	O
</s>
<s>
By	O
way	O
of	O
comparison	O
,	O
the	O
eventual	O
SHA-3	B-Algorithm
standard	O
withstands	O
up	O
to	O
an	O
order	O
-	O
attack	O
.	O
</s>
<s>
FORK-256	B-Algorithm
was	O
added	O
to	O
the	O
Botan	B-Protocol
cryptographic	O
library	O
after	O
its	O
introduction	O
.	O
</s>
<s>
Botan	B-Protocol
developer	O
Jack	O
Lloyd	O
removed	O
the	O
algorithm	O
in	O
2010	O
after	O
concluding	O
the	O
hash	B-Error_Name
suffered	O
from	O
several	O
weaknesses	O
and	O
had	O
never	O
become	O
widely	O
used	O
.	O
</s>
