Only slightly related but on the topic of barcodes and security I'd like to recommend this excellent talk by Felix Lindner, it is quite a few years old but I'd

Only slightly related but on the topic of barcodes and security I'd like to recommend this excellent talk by Felix Lindner, it is quite a few years old but I'd guess stuff like barcode scanners are not the most frequently updated things: Toying with barcodes - https://www.youtube.com/watch?v=QCtdEYnlykA https://www.youtube.com/watch?v=QCtdEYnlykA