So lately I've found something very entertaining. Decoding barcodes used on receipts and other forms of consumer facing items.
I don't mean how the barcode is formatted, what rules that particular format follows. Instead I'm interested in what information is held inside the barcode.
Farmer Boys has a promotion, scan their receipt with the app and earn reward points based on the purchase amount. Which lead me to a simple question of how does the app verify the barcode is a valid transaction. To that end, I've been collecting receipts and correlating the included data.
A typical Farmer Boys barcode contains data similar to 1811344211224. So far I've only had 3 receipts to study. Of that, so far I've found this information.
18 11 344211 224
I'm unsure of the first 2 digits. The second two appear to be correlated to the day, perhaps all four so far are related to the day, but I lack the data to confirm. The next 6 are the check number. The last three appear to be random. I don't find any correlation yet between the receipts I have and the numbers.