An Intra Prediction Mode-based Video Encryption Algorithm in H.264

H.264 is a new video encoding world standard, and the security of video based on H.264 is becoming a research focus. This paper analyses the security shortage of the intra prediction mode (IPM) encryption algorithm proposed by Ahn([1]) from view of perception performance, plaintext scrambling space and key security and then presents an improved IPM encryption algorithm (IPMEA). It encrypts all the IPMs by chaotic pseudo-random sequence, scrambles them for the second time by circulating sequence controlled by key and gives a scheme of key distribution and synchronization. Performance analysis and experimental results show that IPMEA can exhibit higher security than the existing ones and has little impact on code length. Meanwhile, it has low complexity and good real-time property, so it is suitable for real-time video transferring on the network.