Patent ID: 7814555

Claim:
An information network system, comprising a first information apparatus and a second information apparatus, wherein the first information apparatus comprises: a first internal recording medium for storing contents data; a first interface which transfers data relating to the contents data recorded in the first internal recording medium to an external recording medium when the external recording medium is attached to the first information apparatus; and a first transmission/reception unit for connecting the first information apparatus to a network, and the second information apparatus comprises: a second internal recording medium for storing contents data; a second interface; and a second transmission/reception unit for connecting the second information apparatus to a network, wherein: the first internal recording medium comprises an area for storing the contents data and a secured area for storing various kinds of data with limited accessibility, the first information apparatus is configured to: upon receiving a request to move the contents data to the external recording medium while the external recording medium is being attached to the first information apparatus, read out the contents data from the first internal recording medium and transfer the read contents data to the external recording medium after performing compression-conversion to the read contents data; encrypt the contents data by using an encryption key to be stored in the secured area of the first internal recording medium; record contents management information that contains key information relating to the encryption key in the external recording medium; and then delete the key information relating to the encryption key, and the second information apparatus is configured to: when the external recording medium that holds the compression-converted contents data is attached to the second information apparatus, obtain the contents management information from the external recording medium and search the network by using the obtained contents management information to find out the first information apparatus that holds the encrypted contents data corresponding to the contents management information; obtain, through the network, the encrypted contents data from the found first information apparatus; and decrypt the obtained encrypted contents data by using the encryption key contained in the contents management information.