Taming The Wild Card for Mobile Payment

Mastooreh Salajegheh, Bodhi Priyantha, and Jie Liu


Mobile wallets promise to allow people to easily manage their accounts and

to carry less cards. However, the slow adoption of contactless point of

sales (POS) terminals by merchants limits the potential of Near-Field Communication (NFC)

based payment devices. In this paper, we discuss Wild Card, a secure and backward

compatible way to make mobile payment through conventional magnetic stripe

based POS terminals. The device resembles a traditional credit card in its physical

dimensions and stays in the phone case. It can be programmatically set by a NFC-enabled mobile phone to

any card number that the user owns. The key technologies that enables Wild Cards are a fully

programmable magnetic stripe, an energy harvesting system that allow the card to be

charged and programmed by the phone through NFC, and a security mechanism that makes card

information resilient to attacks on mobile devices. With a prototype, we

evaluate the feasibility of Wild Cards in terms of functionality and energy budget.


Publication typeTechReport
PublisherMicrosoft Technical Report
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