Patent ID: 8090952

Claim:
A method comprising: marking a position on a preprinted pattern that has recognizable portions to form a marked pattern, wherein said marking comprises placing a sticker on a portion of said preprinted pattern, wherein said pattern is a continuously repeating preprinted pattern with multiple different recognizable shapes that continuously repeat; using a computer which includes a computer program for obtain a numerical value based on a position where said sticker is placed on said preprinted and continually repeating pattern, where said numerical value corresponds to a placement of the sticker on the portion, said numerical value including at least a first numerical part representing which of a plurality of said different shapes on the preprinted pattern are marked, and a second numerical part representing an orientation of the sticker on said shapes; and using a private encrypting key on said computer for encrypting said numerical value, to form an encrypted signature that is based on where said sticker is placed on said pattern including which of said shapes are marked and the orientation.