Q.1.
RC5 encryption uses Right shift and decryption uses Left shift.
- a) True
- b) False
Q.2.
The below round is the last step in encryption /decryption in RC5.
- a) True
- b) False
Q.3.
The code bellow is the RC5 encryption pseudo code in C language.
- a) The left shift operation (should be right shift)
- b) The right shift operation (should be left shift)
- c) LEi-1 and REi-1 should be LEi and REi
- d) The for loop runs from 1 to r-1 ( not 1 to r)
Q.4.
“RC5 uses the Feistel Structure.”
- a) True
- b) False
Q.5.
Find the error in the Decryption pseudo code for RC5 –
- a) B= RD0 + S [1];
- b) for i = 1 to r do
- c) LDi-1 = ((LDi – S [2xi] >>> RDi-1) ⊕ RDi-1);
- d) A = LD0 – S [0];
Q.6.
Which one of the following is not a RC5 mode of operation?
- a) RC5 block cipher
- b) RC5-Cipher Block Chaining
- c) RC5-Cipher Padding
- d) RC5-CipherText Stealing
Q.7.
Which RC5 mode will have the ciphertext longer than the plaintext by at most the size of a single RC5 block?
- a) RC5 block cipher
- b) RC5-Cipher Block Chaining
- c) RC5-Cipher Block Chaining Pad
- d) RC5-CipherText Stealing
Q.8.
Which RC5 mode of operation is this?
- a) RC5 block cipher
- b) RC5-Cipher Block Chaining
- c) RC5-Cipher Block Chaining Pad
- d) RC5-CipherText Stealing
Q.9.
Which of these is not a characteristic of block ciphers?
- a) Variable key length / block size / number of rounds
- b) Mixed operators, data/key dependent rotation
- c) Key independent S-boxes
- d) More complex key scheduling
Q.10.
Which one of the following RC4 algorithm not used in?
- a) SSL
- b) TLS
- c) FTP
- d) WEP
Q.11.
Till when was the RC4 algorithm kept a secret?
- a) 1990
- b) 1992
- c) 1996
- d) 1994
Q.12.
RC4 algorithm uses the concept of Block Cipher System.
- a) True
- b) False