IC CARD AND ELECTRONIC WATERMARK DATA SUPERIMPOSING DEVICE

摘要

PROBLEM TO BE SOLVED: To perform authentication processing and the burying of electronic watermark data in an IC card having dumper resistance so that only a properly authenticated copyright owner can superimpose specific electronic watermark data. SOLUTION: An external device transmits authentication information such as the ID and password of the copyright owner to an IC card, and the IC card operates authentication processing based on this. When the authentication processing succeeds, data into which electronic watermark data should be buried are successively inputted to the IC card, and electronic watermark data unobservable from the outside are superimposed on the data by an algorithm unobservable from the outside or as necessary in the IC card. The data on which the electronic watermark data are superimposed are returned to the external device, and outputted.