Patent ID: 7957320

Claim:
Method for renewing a group key GK for a secure data exchange in a group of network elements P 1 . . . P n (n=2, 3, . . .) in a network system having a closed peer-to-peer configuration and a virtual synchrony supporting group communication protocol in a communication layer of a system architecture of the network system, wherein said method for group key renewal, when a composition of the group of network elements P 1 . . . P n is changed by the joining of a new network element P n+1 into the group of network elements P 1 . . . P n or by the leaving of a network element P v (1≦v≦n) from the group of network elements P 1 . . . P n , comprises the steps of: selecting a network element P i * (1≦i≦n) from the group of network elements P 1 . . . P n , generating a new group key GK neu by P i * and transferring the new group key GK neu by P i * to all the remaining network elements P k (1≦k≦n, k≠i) of the group of network elements P 1 . . . P n in the changed composition, by performing a key exchange with all the remaining network elements P k in accordance with the Diffie-Hellman principle; wherein a processor implements said steps of selecting, generating and transferring.