WorksheetsSymmetric Cryptography Quiz
Total questions: 10
Worksheet time: 5mins
Which of the following best describes symmetric cryptography?
Uses two keys: one for encryption, another for decryption
Uses the same key for both encryption and decryption
Uses no keys at all
Uses only public keys for encryption
In a stream cipher, encryption is typically performed on:
Fixed-size blocks of data
Entire file at once
One bit or byte at a time
Only the metadata
Which of the following is an example of a block cipher algorithm?
RC4
DES
OTP (One-Time Pad)
Caesar Cipher
What is the primary advantage of stream ciphers over block ciphers?
Higher computational overhead
Suitability for real-time applications
Requires larger key sizes
Always provides better security
Which of the following modes of operation is commonly used with block ciphers to enhance security?
CBC (Cipher Block Chaining)
XOR Mode
ECB (Electronic Code Block) only
Hash Mode
The Electronic Codebook (ECB) mode in block ciphers is considered weak because:
It uses too many keys
It encrypts identical plaintext blocks into identical ciphertext blocks
It is not compatible with symmetric algorithms
It does not support key exchange
Which of the following properties is true for symmetric cryptography?
Faster than asymmetric cryptography
More computationally expensive than asymmetric
Uses separate keys for sender and receiver
Provides built-in key exchange
In a block cipher, if the key length is 128 bits, what does this represent?
The size of each data block
The size of the plaintext message
The size of the encryption key used
The size of the ciphertext
The RC4 cipher is classified as:
Block cipher
Stream cipher
Asymmetric cipher
Hash function
Why are Initialization Vectors (IVs) used in block cipher modes like CBC?
To increase key length
To prevent identical plaintext blocks from producing identical ciphertext
To decrease encryption speed
To convert a block cipher into a stream cipher
