Symmetric Encryption Algorithms

Question 1

RC4

Answer 1

• stream cipher

* accepts keys up to 128 bits in length

Question 2

RC5

Answer 2

• block cipher

* can accept blocks and keys at different lengths

Question 3

RC6

Answer 3

• has 3 key sizes
• 128, 192, and 256
• performs 20 rounds on each block

Question 4

IDEA

Answer 4

.•block cipher

•prcoesses 64 bit with a 128-bit key with 8 rounds

Question 5

CAST

Answer 5

.

Question 6

TWO FISH

Answer 6

• uses 128-bit blocks and variable key lengths (128-, 192-, or 256-bits
• uses up to 16 rounds of substitution and transposition.
• twofish was the runner-up to Rijndael in the selection fo the algorithm of AES

Question 7

BLOWFISH

Answer 7

• uses 64-bit blocks and key lengths anywhere from 32 to 448 bits
• has no effective known cryptanalysis currently

Question 8

DES

Answer 8

• block cipher
• 56-bit key
• divides plaintext into 64-bit and then executes the algorithm 16 times

Question 9

3DES

Answer 9

• 3 rounds of encryption
• 48 iterations in its encryption
• performs better in hardware than software
• 168 bit key

Question 10

AES

Answer 10

• performs three steps on every block (128 bits) of plaintext.
• within step 2, multiple rounds are performed depending upon the key size: a 128-bit key performs 9 rounds, a 192-bit key performs 11 rounds, and a 256-bit key, known as AES-256, uses 13 rounds.

Question 11

SYMMETRIC ENCRYPTION ALGORITHM TRICK

I 
had 
a
REALLY COOL (RC4, RC5, RC6)
IDEA (IDEA)
to walk around the
BLOCK (BLOCK CIPHER)
CAST (CAST)
in a
STREAM (STREAM CIPHER)
for some fish.
I caught
TWOFISH  (TWOFISH)
that were
BLOWFISH (BLOWFISH)
I think it was my
DESTINY (DES, 3DES, AES (RIJNDAEL maker of AES))

Answer 11

.