1. A method for proving an authentication of an original item, wherein a code is assigned to the item according to a set of rules, the code comprising a plurality of modules arranged in an ideal image, wherein at least one barcode content of the item is encoded within the plurality of modules, wherein at least one picture of the printed version of the code is printed onto the item with an original printing device, the method comprising the following steps: i) recording at least one picture of the printed version of the code printed onto the item; ii) decoding the barcode content from the picture; iii) analyzing irregularities in the same picture of step ii) by identifying at least one deviation in the picture with respect to the ideal image and calculating a numerical value describing an individual imperfection profile of the original printing device, wherein the calculating of the numerical value of the individual imperfection profile depends on at least one unique feature inherently related to the original printing device, wherein the at least one unique feature is selected from at least one of a printing technology and a setting of the printing device; iv) storing the individual imperfection profile by at least one of printing the individual imperfection profile onto the item or generating a database record for the item, the database record comprising at least the barcode content and the individual imperfection profile.