Method of marking and of identifying objects marked by electrically conducting elements

摘要

A method of marking and of identifying objects (1) which are non-conductors of electricity by inclusion of conducting masses and detection by passage through a high-frequency electromagnetic field and detection of the variation in the corresponding response signal picked up. Metallic wires (2) each selected from a range of specimens of different electric conductivity are used as marking elements. The responses are measured which are each characteristic of one specimen and of a predetermined code value. The invention applies to the recognition of the authenticity of cards or documents thus previously marked.