GAQM Exam CPEH-001 Topic 6 Question 16 Discussion

A chosen-ciphertext attack (CCA) is an attack model for cryptanalysis in which the cryptanalyst chooses a ciphertext and causes it to be decrypted with an unknown key. Specific forms of this attack are sometimes termed 'lunchtime' or 'midnight' attacks, referring to a scenario in which an attacker gains access to an unattended decryption machine. In cryptography, a man-in-the-middle attack (MITM) is an attack in which an attacker is able to read, insert and modify at will, messages between two parties without either party knowing that the link between them has been compromised. The attacker must be able to observe and intercept messages going between the two victims. A replay attack is a form of network attack in which a valid data transmission is maliciously or fraudulently repeated or delayed. This is carried out either by the originator or by an adversary who intercepts the data and retransmits it, possibly as part of a masquerade attack by IP packet substitution (such as stream cipher attack).