<s>
In	O
cryptography	O
,	O
Q	B-Algorithm
is	O
a	O
block	O
cipher	O
invented	O
by	O
Leslie	O
McBride	O
.	O
</s>
<s>
It	O
operates	O
on	O
blocks	O
of	O
128	O
bits	O
using	O
a	O
substitution	B-Algorithm
–	I-Algorithm
permutation	I-Algorithm
network	I-Algorithm
structure	O
.	O
</s>
<s>
Q	B-Algorithm
uses	O
S-boxes	B-Algorithm
adapted	O
from	O
Rijndael	B-Algorithm
(	O
also	O
known	O
as	O
AES	B-Algorithm
)	O
and	O
Serpent	B-Algorithm
.	O
</s>
<s>
It	O
combines	O
the	O
nonlinear	O
operations	O
from	O
these	O
ciphers	O
,	O
but	O
leaves	O
out	O
all	O
the	O
linear	O
transformations	O
except	O
the	O
permutation	B-Algorithm
.	O
</s>
<s>
Q	B-Algorithm
also	O
uses	O
a	O
constant	O
derived	O
from	O
the	O
golden	O
ratio	O
as	O
a	O
source	O
of	O
"	O
nothing	O
up	O
my	O
sleeve	O
numbers	O
"	O
.	O
</s>
<s>
Q	B-Algorithm
is	O
vulnerable	O
to	O
linear	O
cryptanalysis	O
;	O
Keliher	O
,	O
Meijer	O
,	O
and	O
Tavares	O
have	O
an	O
attack	O
that	O
succeeds	O
with	O
98.4	O
%	O
probability	O
using	O
297	O
known	O
plaintexts	O
.	O
</s>
