Question

In what type of attack does the attacker need access to the cryptosystem, and the ciphertext to be decrypted to yield the desired plaintext results?
Group of answer choices

ciphertext-only

known plaintext

chosen-plaintext

chosen-ciphertext

Answer 1

The type of attack you are describing is a **chosen-ciphertext attack**. In this type of attack, the attacker has access to the cryptosystem and can choose specific ciphertexts to be decrypted, with the goal of obtaining the corresponding plaintext. This is different from other types of attacks like ciphertext-only (where the attacker only has access to ciphertexts), known plaintext (where the attacker has access to both plaintext and corresponding ciphertext), and chosen-plaintext (where the attacker can choose plaintexts to be encrypted).