Quick certification method and apparatus for a vertical handover

A method and apparatus for performing fast authentication for a vertical handover are provided. The method includes requesting a handover from a serving network to a target network and generating a derivative Master Session Key (MSK) for key generation, and transmitting the derivative MSK to the target network. Accordingly, a key negotiation process can start by skipping an access authentication process. Therefore, there is an advantage in that a fast authentication process can be achieved.