Credit cards do not actually contain money; their transactions rely on online systems within financial institutions. However, there is an alternative approach that involves embedding the balance tracking and authorization decisions within the card itself. This concept, known as “epurse” technology, has been used in smart cards in Europe since the 1980s. These cards have onboard microcontrollers that can make decisions and run applications, as well as cryptographic features that make duplication difficult. Smart cards have become widely used for authentication purposes in payment systems and access control. Despite their capabilities, smart cards have not gained widespread adoption in the United States.
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