Symmetric Encryption and Cipher Modes Quiz

In symmetric encryption, the same key is used for both encryption and decryption.

• True

• False

The one-time pad guarantees both confidentiality and message integrity.

• True

• False

ECB mode of operation hides repeating patterns in plaintext.

• True

• False

In the Vernam cipher, decryption uses XOR just like encryption.

• True

• False

CBC mode includes randomness by chaining each block with the previous ciphertext.

• True

• False

CTR mode uses block ciphers to create a keystream like a stream cipher.

• True

• False

AES is a stream cipher developed by the NSA.

• True

• False

A passive adversary can inject messages into a system.

• True

• False

A chosen-plaintext attack is stronger than a ciphertext-only attack.

• True

• False

Using a unique key for every message guarantees confidentiality even in ECB mode.

• True

• False