<s>
The	O
design	O
,	O
published	O
in	O
1997	O
,	O
is	O
a	O
forerunner	O
to	O
Rijndael	B-Algorithm
,	O
which	O
has	O
been	O
adopted	O
as	O
the	O
Advanced	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
.	O
</s>
<s>
Square	O
was	O
introduced	O
together	O
with	O
a	O
new	O
form	O
of	O
cryptanalysis	O
discovered	O
by	O
Lars	O
Knudsen	O
,	O
called	O
the	O
"	O
Square	B-General_Concept
attack	I-General_Concept
"	O
.	O
</s>
<s>
The	O
structure	O
of	O
Square	O
is	O
a	O
substitution	B-Algorithm
–	I-Algorithm
permutation	I-Algorithm
network	I-Algorithm
with	O
eight	O
rounds	O
,	O
operating	O
on	O
128-bit	O
blocks	O
and	O
using	O
a	O
128-bit	O
key	O
.	O
</s>
