Research Of Multilevel Security Network For Multimedia Service

The network wide band as well as the development of digital multimedia technology, have provided the precondition for the multimedia information development. However, the security problem is the bottleneck which is restricting the development of multimedia information. Therefore, with the multimedia technology developing and the band of network wide, researches of the multimedia information security, specially the establishment of wide band network facing to multimedia at the military, the trade, becomes an important challenge topic.This paper makes a thorough study on the security problem of military special network facing to multimedia service, discusses the multilevel security as well as the application of multilevel security, and proposes a practical key management method for multilevel security. There are 4 distinctive features for these research results:1. In view of several kind of multimedia services including ISM system, E-mail system, VoIP, video conference and video broadcast system, we present some solution to their security problems, which can offer multilevel security, Integrity, non-repudiation for multimedia information.2. Analyzing the security of the first proposed dynamitic multilevel key management scheme proposed by Lin in 1997 and showing its fatal that is this can resist backward attack, that is to say, the private key lost will make the new key insecure. Furthermore, we proposed an improved scheme based on this which avoids this shortcoming.3. Based on Chinese remainder theorem, we proposed a practical dynamitic key management scheme. Compared with others based on symmetric encryptions and Elliptic Curves, our scheme under the guaranteed security invariable premise, can provide authentication and one-time pad at the same time, which enhances the scheme secure and uses the band width more efficient.4. Applying multilevel security to secure multimedia services, including multilevel video conference, multilevel video broadcast and so on, which can provide authentication and one-time pad at the same time.