Hi,
If you are using a usb bar code scanner, you will have to generate EAN codes (the EAN code should follow specific rules).
The best at his moment is to generate yourself the serials to have valid EAN codes.
HikaSerial let you export the list of the serials with their data. Using a specific (custom) software, you should be able to scan the code and see if the serial exist, is valid and has been bough (and not already scanned).
Using a QRCode, you can generate a specific url, pointing to your website.
The url can use the "consumption" feature of HikaSerial, it will point to the consume page and thanks to a custom consume plugin, you can let only some specific users consume serials.
So, only you with a smartphone, logged in your website using a specific user, could consume the serial by flashing the QRCode.
Once flash, you will see the consuming page, telling you if the serial is ok, as been right consumed, etc.
This second solution require a very small plugin that we can develop ; it might interest other users for this specific case so it could be a plugin that we could integrate it directly in HikaSerial.
Let me know if this kind of solution can fulfill your requirements.
Regards,