Quiz will ask 20 randomly selected questions with allotted time of . You can take the quiz more than once. Once you submit the quiz, you can review how you have done, the correct the answers for each questions and the explanation for the correct the answer.
7 Modules
Which of the following statements about block ciphers is true?
Block ciphers encrypt data in fixed-size blocks.
Block ciphers can only operate on plaintexts of size 128 bits.
Block ciphers use a symmetric key for both encryption and decryption.
Block ciphers are always faster than stream ciphers.
What is the primary purpose of the Feistel structure in block ciphers?
To ensure that the encryption process is reversible.
To provide diffusion and confusion in the ciphertext.
To simplify the key schedule.
To allow for variable block sizes.
Which of the following is NOT a common mode of operation for block ciphers?
Electronic Codebook (ECB)
Cipher Block Chaining (CBC)
Counter (CTR)
Random Access Memory (RAM)
In the context of block ciphers, what does the term 'key schedule' refer to?
The process of generating a random key.
The method of expanding the key into multiple subkeys.
The time taken to encrypt a block of data.
The algorithm used to decrypt the ciphertext.
Which of the following block ciphers uses a key size of 256 bits as its maximum?
AES
DES
Blowfish
Twofish
7 Modules