Self-adapting method for exchanging composite cipher key and managing session cipher key

The invention discloses a method for self-adaptively exchanging a composite key and managing a session key, which relates to the technology of key exchange and management for information security and authentication among communication entities in communication field. In the method, key exchange in processes of authenticating, encrypting and decrypting can be realized by an ECMQV point-to-point key exchange protocol, an ECDL broadcasting key exchange and management protocol based on public key encryption, and technology of self-adaptive dynamic protocol switching; key interruption in the process of key exchange can be prevented by a key backup technology; and dynamic key and communication terminal management can be realized by self-adaptive communication entity detection technology. The invention has the characteristics of standard interface, automatic reliable communication entity key management, automatic key exchange protocol switch, convenient use and the like, and is particularly for key exchange and mana