At each horizontal point, State is the same for both encryption and

decryption.

DES is a block cipher intended to replace AES for commercial

applications.

The nonlinearity of the S-box is due to the use of the multiplicative

inverse.

Virtually all encryption algorithms, both conventional and publickey,

involve arithmetic operations on integers.

Compared to public-key ciphers such as RSA, the structure of AES

and most symmetric ciphers is quite complex and cannot be

explained as easily as many other cryptographic algorithms.

The ordering of bytes within a matrix is by column.

In the Advanced Encryption Standard the decryption algorithm is

identical to the encryption algorithm.

The S-box is designed to be resistant to known cryptanalytic

attacks.

InvSubBytes is the inverse of ShiftRows.

As with any block cipher, AES can be used to construct a message

authentication code, and for this, only decryption is used.

The Rijndael developers designed the expansion key algorithm to

be resistant to known cryptanalytic attacks.

The transformations AddRoundKey and InvMixColumn alter the

sequence of bytes in State.

The inverse add round key transformation is identical to the

forward add round key transformation because the XOR

operation is its own inverse.

The Advanced Encryption Standard was published by the __________ in 2001.

In Advanced Encryption Standard all operations are performed on __________

bytes.

The AES cipher begins and ends with a(n) _________ stage because any other stage,

applied at the beginning or end, is reversible without knowledge of the key and

would add no security.

A. B.

C. D.

A __________ is a set in which you can do addition, subtraction, multiplication and

division without leaving the set.

Division requires that each nonzero element have a(n) __________ inverse.

In the AES structure both encryption and decryption ciphers begin with a(n)

__________ stage, followed by nine rounds that each include all four stages,

followed by a tenth round of three stages.

The final round of both encryption and decryption of the AES structure consists

of __________ stages.

AES can be implemented very efficiently on an 8-bit processor.

The first row of State is not altered; for the second row a 1-byte circular left

shift is performed; for the third row a 2-byte circular left shift is performed; and

for the fourth row a 3-byte circular left shift is performed. This transformation

is called __________ .

In the AddRoundKey transformation the 128 bits of State are bitwise XORed

with the _________ of the round key.

The encryption round has the structure: