US Patent 11941468 Barcodes with security material and readers for same

A secure indicator includes a substrate, a barcode symbol that has a plurality of barcode modules provided on the substrate, and a security material positioned proximate the barcode symbol on the substrate. The security material is configured to be activated by irradiation at one or more predetermined activation wavelengths. Additionally, the barcode symbol is configured to be read (i) before the security material is activated and (ii) while the security material is activated.