Method and device for testing the trueness of record carriers protectable against falsification

摘要

The invention relates to a method and an apparatus for authentication of record carriers that are to be protected against forgery and which have discrete areas of a magnetic material having exchange anisotropy, triggered by comparing and assigning a by given and opposite directions of magnetization, and after exposure to a predetermined temperature cycle, and it then a remaining zero decaying alternating magnetic field due to the behavior of the magnetic material austauschanisotropen residual magnetization.