The Research And Design Of Multicast Key Management Schemes

The content of this thesis discusses the key element of multicast security-Group Key Management.As the basis of many current Internet applications,multicast has become a hottest research topic now.The problem of the security of group communication key has become urgent to solve,and group key management is the key one of most safety demands.At present,group key management mainly divided into centralized,distributed and hierarchical forms,all of them have their own character and can be used in different applications.In a word:in centralized multicast key management schemes there is a root or a group controller GC,GC is responsible for the entire production,distribution and update of the keys.This scheme is easy to achieve and the response speed is fast,but such schemes rely too much on GC easily lead to a single point of failure.In distributed multicast key management schemes,the point participation in the communication is on a reciprocal basis and the schemes through a key consultative algorithm to generate group key.Such schemes have a good fault-tolerant,but because it lacks of centralized control it leads to the difficulties of the management.In hierarchical grouping multicast key management schemes the members involved in the multicast will be divided into several sub-groups,in each sub-group there is a control node,these control nodes forms multicast key management levelⅠ,the key management of the internal groups belongs to levelⅡ.The two levels can be independent of the choice of a centralized or distributed management schemes and the corresponding architecture.At every level what the scheme chosed will inherit the advantages and disadvantages of the scheme,it inevitably will exists node failure problem.In this paper,first we introduce the correlative knowledge of group key management,and in three group key distribution schemes include centralized,distributed,hierarchical grouping several classic schemes will be selected to complete a detailed exposition and analysis,include centralized GKMP,LKH,OFT,distributed TGDH,LKH and hierarchical grouping of the Iolus,Intra-Domain GKMP schemes.And point out their specific advantages and disadvantages and the scope of use.Through the full analysis of existing schemes this paper proposes hierarchical virtual dynamic subgroups key management scheme based on the construction of large dynamic multicast group and based on two levels of sub-groups and sub-groups members to solve some problems of the large group constructure's group key management and subgroup reconstruction and other issuses.For the request of the establishment of a number of subgroups in large group's different sub-groups and in different sub-groups select members,the traditional schemes use the existing key distribution scheme to achieve.For development,our scheme is on the basis of the original key tree to complete subgroup reconstruction and achieve different levels virtual.It can reduce the transmission of information and key storage space.At the same time it coverts the reality of key subgroups less of the research and solves the problems of large group subgroup's establishment inefficiency.