← Cryptography Basics – CompTIA Security+

CompTIA Security+ Certification Practice Test

Free 5-question sample test with instant feedback. See how ready you are.

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Sample Questions

Question 1

What is the key difference between symmetric and asymmetric encryption?

Answer: Symmetric encryption uses the same key for both encryption and decryption, while asymmetric encryption uses a mathematically related key pair: a public key to encrypt and a private key to decrypt.

Question 2

What is the primary disadvantage of symmetric encryption compared to asymmetric encryption?

Answer: Symmetric encryption requires a secure method to exchange the shared secret key between parties beforehand, creating a key distribution problem.

Question 3

What encryption mode turns a block cipher into a stream cipher by encrypting successive counter values?

Answer: Counter (CTR) mode converts a block cipher into a stream cipher by encrypting an incrementing counter value and XORing the result with plaintext.

Question 4

Why is Electronic Codebook (ECB) mode considered weak for encrypting data?

Answer: ECB encrypts identical plaintext blocks into identical ciphertext blocks, revealing patterns in the data and making it vulnerable to pattern analysis attacks.

Question 5

What is the purpose of an Initialization Vector (IV) in encryption?

Answer: An IV is a random or pseudo-random value used to ensure that identical plaintext blocks produce different ciphertext, preventing pattern detection across encrypted messages.