This is not an attack to the encryption algorithm, but targets the program that handles the encryption.
In this model, the attacker uses one of the methods of "side attack", i.e., he does not attack the data or the algorithm directly, but some component of the process, looking for vulnerabilities that allow him to intercept the original message or the key used.
The attack defined as "man-in-the-middle" therefore seeks to intercept the messages (or the exchange of the secret key) between the sender and recipient, establishing itself "between the two ends" of this communication, allowing it to access the information. This "man-on-the-middle" (a SOFTWARE, remember this!) can be understood in many ways:
The OBAKE suite is prepared for this type of attack within the maximum achieved with current technology:
These methods raise the OBAKE-512 security high enough to resist this attack.
H.C.A. Tilborg et al., "Encyclopedia of Cryptography and Security", H. C. A. v. Tilborg Ed., SpringerScience+Business Media LLC, 2011.
Lookup-Table Attack, https://hashcat.net/wiki/doku.php?id=table_lookup_attack