When data whose storage period is limited by copy control information is temporarily stored in a removable recording medium, the data are encrypted and decoding information (encryption key) necessary to decrypt the encrypted data is held on the device side. By doing so, the data cannot be used beyond a permitted period of the temporary storage. A storage device has an external input/output I/F for removably connecting a removable recording medium; a reception section for receiving copy control information and data (such as video data), the storage period of which data is limited by the copy control information; an encrypting section for encrypting the received data; and a control section for storing the encrypted data in the removable recording medium and storing decryption information (encryption key), necessary to decrypt the encrypted data, in a place in the storage device, outside the removable recording medium. The data stored in the removable recording medium can be reproduced only by the storage device.