A method and a system are provided for recording/reading information data using a first recording medium and a second recording medium each having its own identification data. The method comprises reading first encrypted information data encrypted in accordance with an identification data of the first recording medium and recorded in said first recording medium; encrypting the first encrypted information data in accordance with an identification data of the second recording medium, so as to produce second encrypted information data; recording the second encrypted information data in the second recording medium; reading the second encrypted information data from the second recording medium and decoding the second encrypted information data in accordance with the identification data of the second recording medium; and restoring the second encrypted information data into the first encrypted information data and recording the information data in the first recording medium.