Abstract: A method and system are presented for reading a magnetic tag (10), which is formed by an array of elongated magnetic elements arranged in a spaced-apart parallel relationship in accordance with a pattern of coded information. The tag (10) is located within an interrogating zone where an interrogating field is created. The interrogating field has an alternating traveling magnetic field (102) component with a space phase shift distribution along an axis perpendicular to a direction of force lines of the alternating traveling magnetic field component (102).

Abstract: A magnetic tag is presented, as well as a method for manufacturing such a tag and a detector device and method for use in product authentication. The tag comprises a soft magnetic unit and a hard magnetic unit in its non-magnetized state both carried by a substrate. The soft magnetic unit includes at least one glass-coated amorphous microwire characterized by a large Barkhausen discontinuity and a zero or positive magnetostriction. The hard magnetic unit includes at least one strip-like element of a thickness substantially not exceeding a few tens of microns printed onto the substrate so as to extend along an axis parallel to the microwire. The hard magnetic material has coercivity substantially higher than 1000 Oe. The hard magnetic unit is thus such that, once magnetized, in order to be de-magnetized needs to be subjected to more than a single pulse of an alternating magnetic field of intensity varying from that of at least 250% of the coercive force value of the hard magnetic material to zero.