Fingerprint scanners and devices that generate time-specific codes offer greater security, but they require hardware.

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Now, when inventories fall below a certain level, the checkout scanners instantly order a new batch based on historical demand and delivery time.

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At the time, republican sources said they hoped the move would make it easier for scanners to be introduced if the trials were successful.

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Although barcodes are very easy to transmit securely to mobile devices, the estimated 165 million standard barcode scanners at checkout locations in the U.S. have a very hard time reading them off of reflective screens.

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