Research On Secure Transmission Technology Of Video Surveillance Information

In the existing video surveillance system, data is transmitted from the capture-front to the monitor-end without permutation or encryption. While higher data confidentiality is proposed under circumstances of higher sensitivity cases like private data, business data or political and military data. But video encryption is different from plain data encryption because of its vast datum and other features. And research on the secure transmission technology of MPEG-2 TS is seldom although it is the primary encapsulating standard in the field of video surveillance. At the same time, it is necessary to provide an effective key synchronization scheme for the reasons of packets losing and out-of-order when cipher data is being transmitted. In view of the above characteristics of the video surveillance system, study of the secure transmission technology was carried out on the basis of summing up the existing video encryption methods and algorithms. The related research findings are listed as follows.(1) A scalable method of selective video encryption was proposed based on the deep study of the existing selective methods. This method was composed of several classical methods with advantages of low complexity and high intensity of security. In this thesis, AES-128 OFB was chosen as the sample core algorithm to test the scalable method. The test result showed that it does not depend on specific algorithm and is easy to change the security level dynamically while ensuring data security.(2) A secure data transmission scheme was presented based on MPEG-2 TS. We did a lot of job on the analysis of TS, PES and ES. According to its encapsulation requirements, improvements of MIKEY including the mutual messages and the key derivation were proposed. We tested the improved MIKEY and made sure that the latency is acceptable according to the test result.(3) Two key synchronization schemes were brought forward in line with different level APIs offered by the current video surveillance systems. The key synchronization schemes ensured that the monitor-end can update the offset of the key stream, and consequently, decrypt the cipher stream correctly. We tested the two schemes and analyzed the test result.(4) Integrated the above three parts as well as the access control of the monitor-end and the certificate service system, we proposed a secure video transmission scheme on the basis of MPEG-2 TS.Finally, some open issues in the field of multimedia encryption and the future work were presented.