Research For Audio Security Of IP Digital Broadcasting System

The IP digital broadcasting system is a fully digital audio-broadcasting system based on the IP network. Its physical structure completely syncretize with the IP networks, and the broadcasting system not only authentically achieves the digital audio-broadcasting and audio-live-broadcasting, relies on the advantage of the IP network, it also breaks through the program limit ,space limit and function limit of the traditional broadcasting. The IP digital broadcasting system can fully replace the traditional one, furthermore, it provides a more capacious space for the application of audio-broadcasting. In the IP digital broadcasting system, the data sending and receiving are carried through in the way of multicast. Multicast is an efficient way to exchange data within groups for it achieving low network transmission overheads and high user scalability, Multicast is viewed as a means of data transportation to support the communication of multiple parties.Unlike security of unicast, there are not enough attention and research which are paid to the security problems of multicast. As a communication means of multiple parties, the security problems of multicast are more sophisticated than that of unicast. And the secure multicast schemes that have been requested are not suitable for all scenarios of multicast applications.Based on the security requirement of the IP digital broadcasting system, this paper first introduces the concept of multicast, researches the risk multicast communication faced and the problem multicast security need to be'solved. Then according to the problem multicast security need to be solved, this paper minutely studies three kinds of multicast security guarantee technologies ,the data encryption, the data authentication and the key management. The data encryption is the basic technology that ensures the data's security. Data encryption can be classified by system. This paper minutely describes the algorithm principle and the algorithm security of representative algorithms of the two cryptogram system, and gives the compare of each algorithm. Authentication is the bottleneck of multicast communication. Because of its inherent characteristics, many efficient authentication schemes in unicast communication cannot be applied into multicast communications directly. This paper presents two kinds of multicast authentication technologies, describes the idiographic authentication scheme, and gives the compare of each scheme. The multicast encryption and authentication are both need a key to participate in, so how to make, dispense and update the key became the most important matter of multicast security. This paper introduces the multicast key management schemes at present, and analyses the characteristic of each of them.Lastly, according to the characteristic of the IP digital broadcasting system, this paper designs an audio data security scheme that suit with this system, describes the module function scheme deals with, and gives the actualization of each module.