ການປົກປ້ອງເອກະສານທີມີຄຸນຄ່າຈາກການປອມແປງ ແລະ ວິທີການພິສູດຄວາມເປັນຂອງແທ້ຂອງເອກະສານທີ່ມີຄຸນຄ່າ

The invention relates to the protection of value documents against counterfeit and is intended for use in verifying the authenticity of protected printed products, such as all types of value documents, using an instrument. The invention has the technical result of increasing the level of protection of a document. The value document is provided with a mark containing a fluorescent compound that exhibits both Stokes and anti-Stokes fluorescence and has the composition: Ln 1-x-y-z Yb x Er y Ce z Me I c Me III DP 1-D O 4+D/2-C , where: Me l -Li or Na, Me lll - W or Mo, Ln -Y, La, Gd, 0.1 ≤ x ≤ 0.9; 0.005 ≤ y ≤ 0.2; 0.0001 ≤ z ≤ 0. 1; 0.001 ≤ c ≤ 0.1; 0.001 ≤ d ≤ 0.1; or a compound that has the composition: Ln 2-x-y-z Yb x Er y Ce z 0 2 S; where Ln -Y, La, Gd, 0< x < 0.2; 0.1 ≤ y ≤ 0.4; 0.0001 ≤ z ≤ 0.005. The mark can be produced by printing, for example by offset printing. The method for verifying the authenticity of a value document with all of the above-mentioned features involves detecting a latent protective mark on a value document by measuring and subsequently analyzing the degree to which the intensity of the Stokes and anti-Stokes lines depends on the power density of the exciting radiation.