<s>
The	O
block	O
size	O
is	O
4096	O
bits	O
—	O
unusually	O
large	O
for	O
a	O
block	O
cipher	O
,	O
but	O
a	O
standard	O
disk	B-Application
sector	I-Application
size	O
.	O
</s>
<s>
Mercy	O
uses	O
a	O
6-round	O
Feistel	B-Algorithm
network	I-Algorithm
structure	O
with	O
partial	O
key	B-Algorithm
whitening	I-Algorithm
.	O
</s>
<s>
The	O
round	O
function	O
uses	O
a	O
key-dependent	O
state	B-Architecture
machine	I-Architecture
which	O
borrows	O
some	O
structure	O
from	O
the	O
stream	B-Algorithm
cipher	I-Algorithm
WAKE	B-Algorithm
,	O
with	O
key-dependent	O
S-boxes	B-Algorithm
based	O
on	O
the	O
Nyberg	O
S-boxes	B-Algorithm
also	O
used	O
in	O
AES	B-Algorithm
.	O
</s>
