Video Encryption Algorithm In The Specific Case Study

With the development of multimedia communication, the technology of multimedia information security has become an important subject on networks. Due to the intrinsic characteristics of videos such as gigantic data capacity, high redundancy and the additional requirements for video applications like real-time operation and data-format compliance, traditional encryption algorithms are not suitable to video encryption. In this thesis several familiar video encryption algorithms are investigated, the characteristics of video encryption algorithm is summarized, algorithm performance is analyzed and compared, the application of the algorithms is pointed out, and an improved algorithm for DCT coefficient encryption algorithms is proposed.Based on this, through analyzing the H.264 video compression encoding standard and its encoding feature, a new H.264 video encryption algorithm based on particular conditions is put forward. The algorithm uses the characteristics of energy distributing of the luma and chroma components after DCT transformation in the H.264 encoder, encrypts the DCT coefficients by different methods. Through the experimental result analysis, the encryption algorithm which this thesis brings forward has the characteristic of tight security, low computational complexity and has a small change of the compression rate. So, the algorithm of this thesis satisfies the request of the video transmission in special conditions such as low-bandwidth and high-security.