Cryptanalysis and Attacks CEH Practice Questions (Page 11)

Questions 51–55

1. 51foundation · easy

   What is the primary factor that determines the feasibility of a brute-force attack against a symmetric encryption algorithm?

   • AThe type of plaintext data
   • BThe length of the key
   • CThe encryption mode used
   • DThe hash function used for padding
   Reveal Solution Discussion Select an answer first
2. 52foundation · easy

   What is the primary purpose of a rainbow table?

   • ATo reverse cryptographic hash functions quickly
   • BTo intercept network traffic
   • CTo generate random encryption keys
   • DTo perform frequency analysis on ciphertext
   Reveal Solution Discussion Select an answer first
4. 53foundation · easy

   What is the main advantage of a meet-in-the-middle attack over brute force?

   • AIt uses less memory than brute force
   • BIt reduces the effective key space of double encryption
   • CIt works against any encryption algorithm
   • DIt eliminates the need for known plaintext
   Reveal Solution Discussion Select an answer first
5. 54foundation · easy

   Which type of cipher is most vulnerable to frequency analysis?

   • AA one-time pad
   • BA modern block cipher like AES
   • CA simple substitution cipher
   • DA stream cipher with a truly random keystream
   Reveal Solution Discussion Select an answer first
6. 55application · medium

   An attacker has gained access to a decryption oracle that will decrypt any ciphertext except the target ciphertext. The attacker wants to recover the plaintext of the target ciphertext. Which attack is most appropriate?

   • AKnown-plaintext attack
   • BChosen-plaintext attack
   • CBirthday attack
   • DChosen-ciphertext attack
   Reveal Solution Discussion Select an answer first