I'm not sure I understand what you want to do. Do you actually want to verify the validity of the transaction or secure items against theft? What are barcodes used for? Are they assigned to specific products? Are they unique?
Can you describe the specific usecase better?
Suppose I went to a mall & got myself some t-shirts & tracks, I paid for them via the barcode attached individually on each clothing,
How can the store get to know that I have paid for them, if not then, How can I be caught by the store/system if I try to sneak out of the store?