  With rapid increase of mobile computing and wireless network linkage, the
information exchange between connected systems and within groups increases
heavily. Exchanging confidential information within groups via unsecured
communication channels is a high security threat. In order to prevent third
parties from accessing this data, it is essential to encrypt it. For this
purpose, the group participants need a common group key to enable encrypted
broadcast messages. But efficient key management of secured group communication
is a challenging task, if participants rely on low performance hardware and
small bandwidth. For coordination and distribution, we present the modular
group key management procedure CAKE that is centrally organized and meets
strict security requirements. The lightweight G-IKEv2 protocol in combination
with the key exchange concept of CAKE leads to an efficiently integrated
solution. The hybrid approach combines the advantages of the existing protocols
with the objective to reduce the computation and communication effort. It is
shown that the procedure is more suitable for changing MANET groups than the
existing ones. Moreover, the exchanged group key can be used for any services
which provides a wide range of applications.
