<s>
LEVIATHAN	B-Algorithm
is	O
a	O
stream	B-Algorithm
cipher	I-Algorithm
submitted	O
to	O
NESSIE	O
by	O
Scott	O
Fluhrer	O
and	O
David	O
McGrew	O
.	O
</s>
<s>
It	O
is	O
a	O
seekable	O
stream	B-Algorithm
cipher	I-Algorithm
,	O
which	O
means	O
that	O
the	O
user	O
may	O
efficiently	O
skip	O
forward	O
to	O
any	O
part	O
of	O
the	O
keystream	B-Algorithm
,	O
much	O
like	O
CTR	B-Algorithm
mode	I-Algorithm
or	O
Salsa20	B-Algorithm
,	O
but	O
unlike	O
those	O
ciphers	O
generating	O
contiguous	O
blocks	O
of	O
the	O
keystream	B-Algorithm
is	O
made	O
especially	O
efficient	O
by	O
LEVIATHAN	B-Algorithm
's	O
unique	O
tree	O
structure	O
based	O
stream	O
generation	O
.	O
</s>
<s>
LEVIATHAN	B-Algorithm
achieves	O
around	O
11	O
cycles	O
per	O
byte	O
on	O
a	O
Pentium	B-General_Concept
II	I-General_Concept
processor	O
.	O
</s>
<s>
LEVIATHAN	B-Algorithm
is	O
considered	O
broken	O
due	O
to	O
distinguishing	O
attacks	O
which	O
require	O
236	O
bytes	O
of	O
output	O
and	O
comparable	O
effort	O
.	O
</s>
