Method for changing a group key in a group of network elements in a network system

摘要

The invention relates to a method for changing a group key GK for a secure data exchange in a group of network elements P₁ . . . P_n (n=2, 3, . . . ) in a network system having a closed peer-to-peer configuration and a virtual synchronism supporting group communication protocol in a communication layer of a system architecture of the network system, wherein in the case of a change in a composition of the group of network elements P₁ . . . P_n, caused by the join of a new network element P_n+1 into the group of network elements P₁ . . . P_n or by the leave of a network element P_v (1≦v≦n) from the group of network elements P₁ . . . P_n, a group key renewal, in which a network element P_i* (1≦i≦n) selected from the group of network elements P₁ . . . P_n generates a new group key GK_neu, is carried out and the new group key GK_neu is transferred from the selected network element P_i to all the remaining network elements P_k (1≦k≦n, k≠i) of the group of network elements P₁ . . . P_n in the changed composition, which the selected network element P_i* achieves by carrying out a key exchange with all the remaining network elements P_k in accordance with the Diffie-Hellman principle in order to transfer the new group key GK_neu.