In this research, the HYBRID-III method has been developed to encrypt multiple images. The method, which is obtained by combining diffractive imaging and phase retrieval based intermodulation, can be used to encode multiple images as a single plane. The method contributes to the solution of the bandwidth problem of communication systems since it sends images as a single plane while encrypting them. Users can access only their own plaintext independently of others by using disposable mask codes. The method has been tested in different matrix sizes and different file structures. Moreover, the strength of the method against cyber-attacks is additionally tested.