H.264 is the latest video coding standard developed by ITU-T and ISO/IEC

and its security is becoming a research focus.Several candidate domains are investigated to apply encryption for H.264 and

a new video encryption scheme combining encryption with compression is proposed in this paper.It includes novel simultaneous CAVLC(Context-based Adaptive Variable-Length Coding)and QTC(quantized transform coefficients)encryption and prediction mode

motion vectors scrambling.Theoretical analysis and experimental results show that the scheme is fast

secure

and robust to transmission errors

moreover

it has very limited adverse impact on the compact ratio.