The smartphone is an integral part of our daily routines. The communication and entertainment device of yesteryear has become a serious player with which we increasingly handle sensitive processes, such as payment transactions. At the supermarket checkout, more and more customers are pulling out their smartphones instead of their wallets. Apple Pay, Google Pay or specific banking apps make it possible: simply hold the smartphone in front of the reader of the checkout system, and the transaction is completed without contact. In technological terms, either Bluetooth ® Low Energy (BLE) or Near Field Communication (NFC) is used to complete the authentication and authorize the payment process.