Jaume Ramon Otaegui

1 Introduction Hidden security luminescent marks that become visible upon photoexcitation lie at the core of major anticounterfeiting technologies in banknotes, identification documents, and valuable goods.[1-8] These are often simple labels for visual authentication, though more complex luminescent security elements can also be printed that encode information in a safer mode.[3-8] This is the case of 1D barcodes and 2D QR codes, encrypting binary data as variable emission printed line bars...