Method and apparatus for fingerprinting and authenticating magnetic media

(57) By carrying out DC saturation of the one domain of summary magnetic media (102), and measuring residual DC belt 磁, the method and equipment which measure the remains noise of magnetic media (102) are indicated. An idiomatic magnetic-recording converter can be used for measurement of remains noise. At the time of measurement, the "finger print" of the magnetic media is carried out by digitizing remains noise and recording on the same magnetic media. It is used for checking whether this finger print has original magnetic media, and identifying indigenity (114) later. Thus, the "finger print" of the arbitrary subjects equipped with arbitrary magnetic media or related magnetic media, such as a credit card, a computer program, a compact disk, a video disk, and a cassette tape, is carried out.