A radio apparatus encrypts transmission information to be radio-transmitted at a radio station or decrypts transmission information received through a radio transmission path. The radio apparatus securely encrypts, for transmission, information containing information to be encrypted. Thus, the radio apparatus includes an encryption object identifying unit which identifies from transmission information a portion whose contents and/or attributes that satisfy predetermined conditions, and a transmitting unit which encrypts the identified portion of the transmission information or information containing the identified portion and which radio-transmits the encryption result.