i) generating a first digital image comprising a plurality of colored pixels by printing a printer job with a printer control setting to generate a printout by using the printing device and scanning the printout using a scanning device thereby generating a digital fingerprint;

ii) providing a binary code of identifier information;

iii) mapping the identifier information with the digital fingerprint by determining a binary code of the digital fingerprint and adding the binary code of the identifier information to a color code of the first digital image;

iv) generating a second digital image having a plurality of colored pixels different from the first digital image, by transferring the added binary codes into a color code of the second digital image;

v) printing the second digital image on a substrate thereby generating the security label;

vi) converting color values of the plurality of colored pixels of the second digital image to a secondary color space having at least four primary colors and determining a number of respectively colored pixels for each primary color of the secondary color space;

vii) generating the verification number by converting the determined number of respectively colored pixels for each primary color of the secondary color space to numerals;

wherein the method comprises generating a blockchain of security labels, wherein the second digital image is used as a block and the verification number is used as a hash, wherein method steps i) to vii) are repeated for each subsequent block using the second digital image of preceding blocks as respective first digital images.