In which method used in cryptanalysis does the attacker know a portion of the plaintext and the corresponding ciphertext?
- brute-force
- ciphertext
- chosen-plaintext
- meet-in-the-middle
Answers Explanation & Hints: There are several methods used in cryptanalysis:Brute-force – The attacker tries every possible key knowing that eventually one of them will work.
Ciphertext – The attacker has the ciphertext of several messages encrypted but no knowledge of the underlying plaintext.
Known-Plaintext – The attacker has access to the ciphertext of several messages and knows something about the plaintext underlying that ciphertext.
Chosen-Plaintext – The attacker chooses which data the encryption device encrypts and observes the ciphertext output.
Chosen-Ciphertext – The attacker can choose different ciphertext to be decrypted and has access to the decrypted plaintext.
Meet-in-the-Middle – The attacker knows a portion of the plaintext and the corresponding ciphertext.