388Now at this point we can assume that readers have sufficient practical and theoretical knowledge about the three types of image-based security techniques: visual cryptography, digital image watermarking and steganography. These security approaches are not only able to secure the images but they can also be used to secure other multimedia objects like speech, videos, 3D images, etc. In this chapter we will see what other modifications are required in current image-based security techniques in order to secure other multimedia objects. These issues can be treated as areas of advanced research. After reading this chapter, readers will be familiar with various related fields and can protect all types of digital objects. The Chapter Learning Outcomes(CLO) of this chapter are given below. After reading this chapter, readers will be able to:

Develop his/her own audio watermarking, audio secret sharing and audio-based steganography approaches.

Develop his/her own video watermarking, video secret sharing and video-based steganography approaches.

Understand a few other advanced research areas related to multimedia security.