This paper presents a novel DCT coefficients layered scrambling algorithm (DCLSA) for H.264/AVC based on the deficiencies of current DCT coefficients encryption algorithms in respect of security

compact ratio and signal to noise ratio. According to the characteristics of the 4×4 DCT transform of H.264/AVC

the algorithm first divides the coefficients of every 4×4 block of the same macro block into several layers

and build a coefficients layered model. Then different layer is scrambled

respectively

by security requirements to achieve secure video coding. DCLSA has shown significant advantages on security

compact ratio and signal to noise ratio through performance comparisons with other algorithms and concrete experimental results

thus making it especially suitable for secure network applications.