COMMUNICATION APPARATUS

PROBLEM TO BE SOLVED: To provide a communication apparatus which can encrypt an encrypted content, the encrypted content being distributed through a network, by key data different from the key data assigned to the contents in the network. SOLUTION: An MPU 201 decodes an encryption key EKc received from a key distribution server 103 using a device key Kd unique to a terminal device 101, and the terminal device 101 acquires a content key Kc unique to the content. When uploading the content, it encrypts the content memorized in an inside content memory unit 203 using the content key Kc, a P2P processing unit 208 divides the content, and distributes to other terminal devices 101. Meanwhile, when downloading the content, the P2P processing unit 208 decodes contents collected from a plurality of other terminal devices 101 using the content key Kc, encrypts them using the device key Kd, and stores them in the inside content memory unit 203. COPYRIGHT: (C)2011,JPO&INPIT