Abstract: The present invention relates to a method whereby the mobile station and a visitor location register create and share a ciphering key and an integrity key in order to directly authenticate each other. The communication method in a mobile communication system such as this includes registering the mobile station with the home location register; and having the mobile station and the visitor location register directly authenticate each other and mutually share a ciphering key and an integrity when the mobile station moves to the visitor location register.

Abstract: The present invention relates to a point-to-point communication method that performs mutual authentication and creates link keys without using a master key. The point-to-point communication method can include authentication by exchanging authentication information between a first node and a second node from among the plural nodes; and having each of the first node and the second node create a link key, after the authentication is completed. During the authentication, the authentication information uses a secret key of a corresponding coordinator (node).