Cryptography Unit2

In symmetric key cryptography, the same key is used for:

• Encryption and decryption of data.
• Key generation and storage.
• Only decryption of data.
• Only encryption of data.

Which of the following is a symmetric key algorithm?

• Blowfish
• SHA-256
• AES
• RSA

DES stands for:

• Data Encryption Standard
• Data Encoding Standard
• Digital Encryption System
• Data Encryption Service

DES has a block size of:

• 64 bits
• 256 bits
• 32 bits
• 128 bits

The number of rounds in DES is:

• 16
• 12
• 8
• 20

AES supports key sizes of:

• 128, 192, and 256 bits
• 128 and 512 bits
• 128, 256, and 512 bits
• 64, 128, and 192 bits

The block size in AES is fixed at:

• 64 bits
• 256 bits
• 128 bits
• 512 bits

The number of rounds in AES-128 is:

• 8
• 12
• 14
• 10

Which operation is not used in AES?

• XOR
• Addition
• Subtraction
• Multiplication

Linear cryptanalysis uses:

• Statistical analysis of the cipher's key.
• Brute force attacks on the cipher.
• Substitution techniques for encryption.
• Linear approximations of the cipher's behavior.