Untitled Presentation

Open Ended

Why is it important for the substitution in an S-box to be one-to-one in cryptographic algorithms?

Multiple Choice

Which of the following best describes the role of an S-box in the Substitution–Permutation Model?

• It substitutes a small block of bits with another block of bits, ensuring invertibility.

• It permutes all the bits in the input.

• It generates the round key for each round.

• It combines the output using XOR operation.

Multiple Choice

Which cryptographic structure is illustrated in the diagram with multiple rounds of substitution and permutation, and what is its primary purpose?

• Substitution-Permutation Network, used for block ciphers

• Feistel Network, used for stream ciphers

• RSA Algorithm, used for public key encryption

• Hash Function, used for data integrity

Open Ended

Explain the main difference between symmetric and asymmetric encryption, using AES as an example.

Multiple Choice

What are the possible key sizes and block size for the Advanced Encryption Standard (AES)?

• Key sizes: 128, 192, or 256 bits; Block size: 128 bits

• Key sizes: 64, 128, or 256 bits; Block size: 64 bits

• Key sizes: 128, 192, or 256 bits; Block size: 256 bits

• Key sizes: 192, 256, or 512 bits; Block size: 128 bits

Multiple Choice

Which steps are repeated in each round of the AES encryption process, and which step is omitted in the last round?

• SubBytes, ShiftRows, MixColumns are repeated; MixColumns is omitted in the last round

• AddRoundKey is repeated; SubBytes is omitted in the last round

• ShiftRows, MixColumns are repeated; AddRoundKey is omitted in the last round

• SubBytes, MixColumns are repeated; ShiftRows is omitted in the last round

Multiple Choice

What is the purpose of the SubBytes step in the AES algorithm, as shown in the diagram?

• To provide non-linearity by substituting bytes using an S-box

• To shift the rows of the state matrix

• To mix the columns for diffusion

• To add the round key to the state

Multiple Choice

Which step in AES involves shifting the rows of the state matrix by different offsets?

• ShiftRows

• MixColumns

• AddRoundKey

• SubBytes

Multiple Choice

What is the main purpose of the MixColumns step in AES encryption?

• To permute the columns for diffusion

• To substitute bytes for confusion

• To add the round key to the state

• To shift the rows for diffusion

Multiple Choice

In the AddRoundKey step, which operation is performed between the state and the round key?

• Bitwise AND

• Bitwise OR

• Bitwise XOR

• Addition modulo 256

Open Ended

Explain how the state is represented in AES and how it relates to the block size.

Multiple Select

Select all valid AES key sizes from the following options.

• 128 bits

• 160 bits

• 192 bits

• 256 bits

Multiple Choice

Which of the following is NOT a characteristic of symmetric key cryptography?

• Two parties MUST trust each other

• Both share the same key

• Typically slower

• Examples include RSA and ECC

Multiple Select

Which of the following statements about asymmetric encryption are correct?

• It uses two keys: a public key and a private key.

• It is typically faster than symmetric encryption.

• It relies on number theory concepts.

• Both parties must trust each other.

Open Ended

Explain the main differences between symmetric key and asymmetric key cryptography, and discuss scenarios where one might be preferred over the other.

Multiple Choice

In the context of asymmetric encryption for confidentiality, whose public key does Bob use to encrypt a message intended for Alice?

• Bob's public key

• Alice's public key

• Bob's private key

• Alice's private key

Open Ended

Describe the process of authentication using asymmetric encryption as shown in the diagram. What role do private and public keys play in this process?

Multiple Choice

Which of the following is NOT an application of asymmetric encryption?

• Encryption/decryption

• Digital signature

• Key exchange

• Symmetric key generation

Multiple Select

Which steps are involved in the process of digital signatures? Select all that apply.

• Hashing the message

• Signing with sender's private key

• Encrypting with receiver's public key

• Verifying with sender's public key

Open Ended

Describe the sequence of steps involved in creating and verifying a digital envelope carrying a signed message.

Multiple Choice

Which protocol in the SSL architecture is responsible for establishing a secure connection between client and server?

• SSL Record Protocol

• SSL Handshake Protocol

• SSL Alert Protocol

• SSL Change Cipher Spec Protocol

Open Ended

How do S-boxes and P-boxes work together to ensure security in the Substitution–Permutation Model?

Multiple Choice

What is the main function of an S-box in the Substitution–Permutation Model?

• To substitute a small block of bits by another block of bits

• To permute all the bits from S-boxes

• To generate the round key

• To perform XOR operations