CNS quiz-2

What does DES stand for in cryptography?

• Data Encryption Standard

• Digital Encryption System

• Data Encoding Standard

• Data Encryption Service

Which encryption standard is considered more secure, DES or AES?

• RC4

• AES

• Blowfish

• RSA

What is the key size used in AES encryption?

• 1024 bits

• 64 bits

• 512 bits

• 128, 192, or 256 bits

Describe the main purpose of a block cipher.

• To compress data for faster transmission.

• The main purpose of a block cipher is to provide data confidentiality through encryption.

• To create digital signatures for authentication.

• To manage access control for files.

What does IDEA stand for in the context of encryption?

• International Digital Encryption Algorithm

• Integrated Data Encryption Approach

• Interconnected Data Encryption Association

• International Data Encryption Algorithm

Name one mode of operation for block ciphers.

• Output Feedback (OFB)

• Electronic Codebook (ECB)

• Cipher Block Chaining (CBC)

• Counter (CTR)

What is a significant distinction between AES and DES in terms of encryption method?

• AES employs a substitution-permutation network, whereas DES uses a Feistel network.

• AES is a block cipher, while DES is a stream cipher.

• AES is less secure than DES due to its simpler structure.

• AES and DES both utilize the same encryption method.

What is the significance of the key schedule in AES?

• The key schedule reduces the number of rounds in AES encryption.

• The key schedule generates round keys for each encryption round, enhancing security and complexity.

• The key schedule is responsible for decrypting the data directly.

• The key schedule is used to initialize the AES algorithm only once.

Explain the concept of a block cipher mode of operation.

• A block cipher mode of operation is a method for decrypting data using a stream cipher.

• A block cipher mode of operation is a technique for compressing data before encryption.

• A block cipher mode of operation is a way to encrypt data using a single key for all blocks.

• A block cipher mode of operation is a method for encrypting data using a block cipher, allowing for the encryption of data larger than the cipher's block size.

What is the primary advantage of using AES over older encryption standards?

• Stronger security and efficiency.

• Limited key sizes and complexity.

• No compatibility with modern systems.

• Weaker security and slower performance.