1
.
The
Advanced
Encryption
Standard
(
AES
)
is
a
____________________
-
key
block
cipher
published
by
the
National
Institute
of
Standards
and
Technology
(
NIST
)
in
December
2001
.
2
.
AES
is
a
non
-
____________________
cipher
that
encrypts
and
____________________
a
data
block
of
128
bits
.
It
uses
10
,
12
,
or
14
rounds
.
The
key
size
,
which
can
be
128
,
192
,
or
256
bits
,
depends
on
the
number
of
rounds
.
3
.
To
provide
security
,
AES
uses
four
types
of
transformations
:
substitution
,
____________________
,
mixing
,
and
key
-
adding
.
4
.
In
the
decryption
,
the
transformation
is
called
____________________
and
the
shifting
is
to
the
right
.
5
.
The
InvMixColumns
transformation
is
basically
the
same
as
the
____________________
transformation
.
6
.
Each
round
key
in
AES
depends
on
the
____________________
round
key
.
The
dependency
,
however
,
is
nonlinear
because
of
SubWord
transformation
.
The
addition
of
the
round
constants
also
guarantees
that
each
round
key
will
be
different
from
the
previous
one
.
7
.
AES
uses
four
types
of
transformations
for
encryption
and
decryption
.
In
the
standard
,
the
encryption
algorithm
is
referred
to
as
the
cipher
and
the
decryption
algorithm
as
the
____________________
cipher
.
8
.
AES
can
be
implemented
in
software
,
hardware
,
and
____________________
.
The
implementation
can
use
table
lookup
process
or
routines
that
use
a
well
-
defined
algebraic
structure
.
