Digital holography together with double random phase Fresnel plane (input plane and intermediate Fresnel plane) encoding is used for joint encryption and copyright protection of image and audio data. The image is the host data and 2-D sound map created from audio data serves as copyright information. The host image and sound map are encoded as intensity and phase of a complex function respectively and serves as a complex input image for a digital holographic processor. The proposed method can be interpreted as an audio watermarking since both visual and audio perception takes place simultaneously during reconstruction. The tolerance against partial loss of secured information has been analyzed. From a partial segment of jointly protected image-sound complex encrypted Fresnel field, the data can be reconstructed within an acceptable quality to recognize the copyright audio by human subjects. The proof of concept of the proposed method is demonstrated by numerical simulations using position phase shifting digital holography. © Research India Publications.