CEH Practice Question: Advanced Topics: Wireless, Cloud, IoT, Cryptography

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Uses a single shared key for encryption and decryption

  Why this is correct

  Symmetric encryption algorithms, such as AES or DES, fundamentally rely on a singular, identical secret key for both the transformation of plaintext into ciphertext and the subsequent reversal of ciphertext back into plaintext. This shared secret must be securely exchanged between communicating parties prior to any encrypted data transmission. The efficiency of this method stems from using the same cryptographic key for both operations, simplifying key management for individual sessions.

• ✓

  Faster than asymmetric encryption

  Why this is correct

  Symmetric encryption algorithms are significantly faster and more efficient in terms of computational overhead compared to their asymmetric counterparts. This speed advantage arises because symmetric algorithms typically involve simpler mathematical operations, making them ideal for encrypting large volumes of data. The reduced processing power required allows for higher throughput and lower latency in secure communications.

• ✗

  Slower than asymmetric encryption

  Why it's wrong here

  This statement is incorrect because symmetric encryption algorithms are, in fact, considerably faster than asymmetric encryption algorithms. Symmetric methods utilize less complex mathematical operations, requiring fewer computational resources to encrypt and decrypt data. Consequently, they are preferred for bulk data encryption where high performance and throughput are critical, making them demonstrably quicker.

• ✗

  Provides non-repudiation

  Why it's wrong here

  Symmetric encryption does not inherently provide non-repudiation, which is the assurance that a sender cannot deny having sent a message. Since both the sender and receiver possess the identical shared secret key, either party could theoretically have generated the ciphertext. Non-repudiation is typically achieved through asymmetric cryptography, specifically using digital signatures where the sender's unique private key creates a verifiable signature.

• ✗

  Uses a pair of public and private keys

  Why it's wrong here

  This characteristic describes asymmetric encryption, not symmetric encryption. Asymmetric cryptography, also known as public-key cryptography, employs a mathematically linked pair of keys: a public key for encryption and a private key for decryption. Symmetric encryption, by contrast, relies solely on a single, identical secret key for both cryptographic operations, making this statement fundamentally incorrect for symmetric systems.

Go deeper

Related to this question