ISC2 CISSP Practice Question

In a chosen-ciphertext attack, the attacker has the ability to decrypt arbitrary ciphertext messages of their choosing (except for the target ciphertext they're trying to break). This is a powerful attack model where the adversary can submit ciphertexts to a decryption mechanism, which returns the corresponding plaintexts. By analyzing the relationship between chosen ciphertexts and their resulting plaintexts, an attacker may be able to determine information about the decryption function or key, eventually allowing them to decrypt the actual target ciphertext. This differs from other attack models like known-plaintext attacks (where attackers have pairs of plaintexts and their corresponding ciphertexts) or ciphertext-only attacks (where attackers only have access to ciphertexts).