Abstract: Key management protocol is the base of secure communications between satellite network nodes. Character of key management protocol in the terms of satellite network environment was analyzed. A distributed key establishment scheme combined with centralized one was proposed for LEO satellite network. hhen, an improved key management protocol was given with new clustered rekeying mathod. At the end, it was analyzed and checked. The result indicates that it could help to tighten security with shorter key updating period.

Key words: LEO satellite network, ECC, Key management, Network security