Card recording medium, certifying method and apparatus for the recording medium, forming system for recording medium, enciphering system, decoder therefor, and recording medium

摘要

In a card type recording medium containing a data area where data containing ID information of a holder are recorded, and an image area where image data are recorded, in the image area are recorded second image data which are generated by transforming first image data specifying the holder to frequency-area data, adding the transformed frequency-area data with the ID information and inversely transforming the added data to image signals.