Key distribution method, terminal device and key distribution center

A key distribution method, a terminal device and a key distribution center are provided. The method includes the steps that the first entity and the second entity wanting to communicate respectively generate a pair of temporary public and private keys, and the pair of temporary public and private keys generated respectively by the first entity and the second entity are used to apply to the key distribution center to obtain the communication session key. The method of this invention is based on principle of three-element peer authentication (TePA) and use the public key encryption technology. It distributes keys to the entities wanting to communicate by the key distribution center KDC. It realizes the security distribution and dynamic updating of the communication key, and has the perfect forward secrecy PFS. It solves the problems that the key distribution center had to manage a plenty of the keys by the conventional method and the users had to store a cryptic key for a long time and the communication keys had not forward secrecy and so on. The scheme of this invention may be used in mobile communication network system and also may be used in other communication systems.