A mobile communication terminal moves and backs up a content, which was downloaded from a content server, to a personal computer. When the mobile communication terminal receives an encryption key generation request from the personal computer via a cable, the mobile communication terminal extracts information to be used for generating the encryption key and generates the encryption key by using the extracted information and own telephone number. And the generated encryption key is transmitted to the personal computer via the cable. Accordingly, the backed up and moved content can be reproduced with the personal computer.