To solve the scalability problem in Application Level Multicast(ALM) group key management scheme.MGKT,a multi-group key tree based large-scale ALM group key management scheme is proposed.

• 针对现有应用层组播组密钥管理方案可扩展性差等问题,设计一种适用于大规模应用层组播的基于多组密钥树的组密钥管理方案MGKT。