Patent ID: 7813509

Claim:
A key distribution method applied in the Next Generation Network comprising a terminal, a soft switch and an authentication center, comprising: the terminal sending a registration request message to the soft switch for a registration; the soft switch sending an authentication request message to the authentication center for the authentication for the terminal; and the authentication center authenticating the terminal, generating a session key for the terminal and the soft switch, and sending the session key to the soft switch, so as to be distributed to the terminal upon a successful authentication; wherein the step of the authentication center authenticating the terminal comprises: the authentication center generating a first verification word for the terminal according to a key Kc shared with the terminal, encrypting the session key with the shared key Kc, and returning the encrypted session key and the first verification word to the soft switch; the soft switch returning a registration failure response message to the terminal to notify the terminal of a registration failure; the terminal generating a second verification word according to the key Kc shared with the authentication center, and sending a registration message containing the second verification word to the soft switch for a registration again; and the soft switch authenticating the terminal according to the first verification word and the second verification word; wherein the step of the soft switch distributing the session key to the terminal comprises: the soft switch returning to the terminal a registration success response message containing the session key encrypted with the shared key Kc, and sending a terminal authentication success message to the authentication center; and the terminal decrypting the session key encrypted by the authentication center according to the shared key Kc.