Reading device to read a composite mark that includes a non-clonal physical function to fight counterfeiting

摘要

A method for reading with a reader device a composite security mark comprising a non-clonable physical function, PUF, and a corresponding first digital signature or a pointer indicating a source where said first digital signature can be accessed, the method comprising the following steps: a stimulation step, wherein a physical challenge is created according to a predetermined challenge-response authentication scheme corresponding to the PUF and applied to a PUF; a detection step, wherein a response generated by the PUF is detected according to the challenge-response authentication scheme in reaction to the challenge and a digital signal is generated representing the response; a processing step, wherein the digital signal is processed to generate a summary value of the response by applying a predetermined cryptographic summary function to the digital signal; an output stage, where the data representing the summary value generated as a first read result is output; and characterized in that it further comprises an acquisition stage, wherein the composite security mark is read to acquire said first digital signature of the composite security mark or the source indicated by the pointer, respectively; wherein in the output stage a representation of the first acquired digital signature and / or a matching output that indicates whether, according to at least one predetermined matching criteria, a summary value provided and signed by the first acquired digital signature is generated matches the summary value generated from the response to the challenge; wherein the acquisition stage further comprises acquiring from the composite security mark a second digital signature or a pointer indicating a source where a second particular digital signature belonging to the mark can be accessed; and wherein the output stage further comprises issuing a representation of the second acquired digital signature as a second reading result.