Abstract: To solve the large delay problem of video coding by using the chaotic encryption, a fast security encryption algorithm for H.264/AVC video is proposed. First, a key generation scheme is designed. Four groups of chaotic sequences are generated with four-dimensional Quantum Cellular neural Network (QCNN) iteration, the first three groups are used for chaotic sequence pool, and the other one is used to generate the initial value of the Logistic map to increase the dynamics of the initial value. Then, to avoid repeatedly solving the high dimensional chaotic systems, the sequence of the calculation key is selected from the chaotic sequence pool according to the index generated by the Logistic map. After calculation, the encryption key is obtained, which realizes the fast generation of the key. Finally, some key elements, such as partial sign bits and information bits in video coding, are effectively encrypted for reducing the amount of encrypted data. Experiments show that the proposed encryption algorithm for 70 frames of video coding delay is less than 0.6%. Through the key space analysis, NIST SP 800-22 test, known plaintext attack and inference attack experiment analysis, it is shown that the proposed video encryption algorithm has the advantages of large key space, good random key, strong attack resistance and high security. In addition, the algorithm does not change the video compression ratio to conform video encoding format specification. By quickly generating secure keys with only encrypting the key video syntax elements, the H.264/AVC video encryption delay is effectively reduced.

Key words: computer application, video encryption, H.264/AVC, quantum cellular neural network