<s>
In	O
cryptography	O
,	O
the	O
Generalized	O
DES	B-Algorithm
Scheme	O
(	O
GDES	B-Algorithm
or	O
G-DES	B-Algorithm
)	O
is	O
a	O
variant	O
of	O
the	O
DES	B-Algorithm
symmetric-key	B-Algorithm
block	O
cipher	O
designed	O
with	O
the	O
intention	O
of	O
speeding	O
up	O
the	O
encryption	O
process	O
while	O
improving	O
its	O
security	O
.	O
</s>
<s>
In	O
1990	O
,	O
Eli	O
Biham	O
and	O
Adi	O
Shamir	O
showed	O
that	O
GDES	B-Algorithm
was	O
vulnerable	O
to	O
differential	O
cryptanalysis	O
,	O
and	O
that	O
any	O
GDES	B-Algorithm
variant	O
faster	O
than	O
DES	B-Algorithm
is	O
also	O
less	O
secure	O
than	O
DES	B-Algorithm
.	O
</s>
<s>
GDES	B-Algorithm
generalizes	O
the	O
Feistel	B-Algorithm
network	I-Algorithm
structure	O
of	O
DES	B-Algorithm
to	O
larger	O
block	O
sizes	O
.	O
</s>
<s>
In	O
each	O
round	O
,	O
the	O
DES	B-Algorithm
round	O
function	O
is	O
applied	O
to	O
the	O
rightmost	O
32-bit	O
subblock	O
,	O
and	O
the	O
result	O
is	O
XORed	O
with	O
all	O
the	O
other	O
parts	O
.	O
</s>
