Dual encryption protocol for scalable secure group communication

A multicast group comprising:

• a logical tree structure, said structure having a sender node and said sender node having one or more child nodes;
• a key group, said key group defined by a child node of said sender node and all descendant nodes of said child node, said sender node issuing a first encryption key to member nodes of said key group after verifying that said member nodes have not previously requested to join the multicast group, said member nodes defined by nodes of said key group;
• and
• a subgroup, said subgroup defined by a subgroup manager and child nodes of said subgroup manager, said subgroup manager issuing a second encryption key to said subgroup, both said first encryption key and said second encryption key required to access a data encryption key, said data encryption key providing access to multicast data.

A system for implementing scalable secure multicasting comprising:

• a hierarchical structure of nodes logically organized as one or more subgroups each subgroup having an associated subgroup manager and at least one child node that functions as the recipient of multicast information;
• said subgroup manager issuing a subgroup key for use by its associated subgroup;
• said hierarchical structure of nodes further having a root node that functions as the sender of multicast information, the root node and its hierarchically adjacent children logically defining a plurality of key groups;
• said sender separately issuing a key group key to each of said key groups;
• said sender supplying multicasting information to said host using a dual encryption protocol such that both subgroup key and key group key are required at said host to decrypt the multicast information, one or more of said subgroup managers being a participant subgroup manager, wherein said participant subgroup managers are not entitled to the multicast information;
• and
• said sender determining whether said participant subgroup managers are in a member database.