Recent advances in digital media technologies have created a large number of secured multimedia applications. Those applications and services are often deployed in a wireless network environment. This book presents a new model for the three tier transcoding architecture. The objective of that model is to minimize the transcoding process while upholding the security aspect of the stream. In addition, a novel security technique is proposed. This technique is mainly designed to provide more security on higher levels of applications. A novel and simple scrambling method was proposed too. The results of implementing the developed security techniques according to the selective encryption equation of the off-line-scenario are deployed and analyzed.