Mobipay was a mobile payment service that was deployed in Spain from 2001 to 2009. It allowed authorizing payments with credit or debit cards such as VISA and MasterCard associated with the mobile phone. With this system it was not necessary to send the data of the card over the internet.
The communication was made through interactive USSD messages between the mobile phone and the Mobipay node, in the form of a question-answer. The option to use SMS was also enabled.
When making a payment with Mobipay, a USSD message is received on the mobile phone that informs of the operation that is being carried out (trade and amount) and requests that it be authorized by responding with a Personal Identification Number (PIN), number secret that only the user knows. Several cards can be associated to the same phone (mobile wallet) although there is one selected by default.
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