Abstract: In order to solve the encryption computing efficiency and flexibility issues when applying traditional data cryptographic algorithms on video content protection, this paper proposed a new selective video content encryption algorithm which exploits the characteristics of H.264/AVC CABAC entropy encoder. By introducing pseudorandomization in CABAC entropy encoder’s binary arithmetic encoding stage, the new algorithm can employ the entropy encoder itself to fulfill the basic encryption operation. In the meantime, the video content data unit being encrypted can be selected flexibly according to its importance. The experimental results show that the proposed algorithm does not impair the compression efficiency of the entropy encoder, and the encrypted video stream hides the visual characteristics of the original video content successfully.