 Known-plaintext attack

A known-plaintext attack (KPA) is a type of cryptanalytic attack in which the attacker has access to both the plaintext (the original unencrypted message) and its corresponding ciphertext (the encrypted message). The goal of the attacker is to use this information to derive the key or to find vulnerabilities in the encryption algorithm. In a known-plaintext attack, the attacker can analyze how specific pieces of plaintext are transformed into ciphertext.