SummarySpace key management schemes play a critical role in space information network security services. However, the existing space key management schemes are inefficient. To overcome these problems, this paper proposed a cluster group key management scheme, in which the space nodes are divided into different clusters. The ground control center (GCC) is used as a private key generation center. The threshold technique based on low‐density parity‐check code (LDPC) is used in the group key management of the cluster‐heads. The key escrow is transferred to GCC, which is a compromise of efficiency and security. The logical key hierarchy is used to manage the group key of the cluster. Furthermore, the bilinear paring‐based cryptosystem is employed to provide the identification. The formalized security proof of the protocol using the Extended Canetti–Krawczyk (ECK) model is introduced to prove the authentication and security. The consistency, forward secrecy, backward secrecy, ability to against the collusion attack and performance are analyzed and simulated. The result shows that the proposed scheme takes lower storage cost and computational cost.