Group Key Establishment Analysis
1.2.2 Group Key Establishment
The overview of key establishment in group communication is discussed with the basic service and additional security properties, fault tolerance and group management.
1.2.2.1 Basic Service and Additional Security Properties
The basic service and security properties of a key establishment are roughly the same for the n-party case, i.e., groups, as they are for the two-party case described above. The main differences which have to be considered are as follows. On the one hand, due to the dynamic nature of a group, it is more difficult to reason about the honesty of parties. A party might be considered trusted in respect to its “legal” membership period. However, it also might try to misuse this time to prepare access to the group at other “illegal” membership periods, potentially even in collusion with other former group members. In fact, a number of group key …show more content…
Simple group key authentication is the sufficient and only practical form of authentication in the case of large asymmetric groups where a static party controls access to the group and members do not know each other, e.g., in video-on-demand applications. However, in DPGs, where the roles of group members are symmetric and a common agreement on the group membership is essential, mutual group key authentication is more desirable and more natural than simple group key authentication. In groups, the verification of the authenticity does not always have to be direct as in the two-party case. It also can be indirect via some other group member(s). This requires additional trust assumptions in these intermediary group members. However, these trust assumptions are quite natural when trust insiders not to give away the common group key. Similarly, in extending explicit key authentication, a confirmation which is either direct and pairwise or indirect is
The overview of key establishment in group communication is discussed with the basic service and additional security properties, fault tolerance and group management.
1.2.2.1 Basic Service and Additional Security Properties
The basic service and security properties of a key establishment are roughly the same for the n-party case, i.e., groups, as they are for the two-party case described above. The main differences which have to be considered are as follows. On the one hand, due to the dynamic nature of a group, it is more difficult to reason about the honesty of parties. A party might be considered trusted in respect to its “legal” membership period. However, it also might try to misuse this time to prepare access to the group at other “illegal” membership periods, potentially even in collusion with other former group members. In fact, a number of group key …show more content…
Simple group key authentication is the sufficient and only practical form of authentication in the case of large asymmetric groups where a static party controls access to the group and members do not know each other, e.g., in video-on-demand applications. However, in DPGs, where the roles of group members are symmetric and a common agreement on the group membership is essential, mutual group key authentication is more desirable and more natural than simple group key authentication. In groups, the verification of the authenticity does not always have to be direct as in the two-party case. It also can be indirect via some other group member(s). This requires additional trust assumptions in these intermediary group members. However, these trust assumptions are quite natural when trust insiders not to give away the common group key. Similarly, in extending explicit key authentication, a confirmation which is either direct and pairwise or indirect is