Apparatus and method for security in wireless network using mobile ip

An apparatus and a method for security in a wireless network using a mobile IP(Internet Protocol) are provided to solve security problems during return-routability, by enabling a mobile node to generate an encryption text during return routability for binding update and transmit the generated encryption text with a HoTI message or CoTI message and enabling a correspondent node to decode and verify the received encryption text. In a return routability method of a mobile node in a wireless network supporting a mobile IP, a home test initialization message including information required in generating and verifying an encryption text is generated. A hash value is generated by concatenating a home address, an address of a correspondent node and a home initialization cookie and then hashing the concatenated result. An encryption text is generated by encrypting the generated hash value with a secret key of the mobile node. The encryption text is added to the home test initialization message and then is transmitted to the correspondent node via a home agent.