A mobile node (400) capable of establishing an ad hoc network routing is disclosed. The mobile node comprises a transmitting/receiving unit (426) for communicating with other communication unit and a routing request generator (422) for generating a routing request message for requiring an ad hoc network routing. The mobile node further comprises: an address storage (427) for storing an address of the mobile node (400) and an address of a receiving node; a random number generator (430) for generating a random number; a certificate issuing unit (440) for issuing a certificate of the mobile node (400); a digital signature creator (450) for creating a digital signature of the mobile node (400); and a controller (424) for transmitting/receiving the routing request message accompanied by the address of the mobile node, the address of the receiving node, the random number, the certificate and the digital signature via the transmitting/receiving unit, according to an ad hoc network protocol.