Modern buyers enjoy the convenience of digital payments, but not all
points of sale always have an Internet connection. Trusting the buyer’s
device to honestly report that a payment was definitively made puts merchant’s revenue at risk. We present an inexpensive and usable solution for merchants to verify that a buyer correctly completed a payment even when the point of sale is offline.
The talk will cover the design details and talk about the current implementation using GNU Taler: a free software, privacy focused and online payment which is built with some properties of cash.