A content reproducing device decrypts and outputs an encrypted content encrypted by a content key received from a content transmitting device. The content reproducing device includes a content key obtaining unit for obtaining the content key, and a storage unit for storing the key unique to the content transmitting device, usage restriction information to restrict the usage of the key unique to the content transmitting device, and link information indicating linking of the content transmitting device and the content reproducing device. The content reproducing device also includes a key decryption unit for decrypting the content key with the key unique to the content transmitting device in the event that the content reproducing device is included in the stored link information unit, and a usage control unit for restricting usage of the key unique to the content transmitting device, based on the stored usage restriction information.