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I want to know that is there any specific command available by using which I can send the terminal a command and the terminal will start to communicate with the android device from the beginning of the transaction. Suppose, terminal is sending me the following APDU request when it first communicate with the android payment app: 00A404000E325041592E5359532E444446303100 . Then if I want to ask the terminal to send again this apdu request then what Should I send to the terminal in response to this apdu request. Like I want the following scenario:

terminal send apdu req to device : 00A404000E325041592E5359532E444446303100
device send some command to terminal : XX
then the terminal sending apdu req to the device : 00A404000E325041592E5359532E444446303100

what will be the value of XX ?

faysal
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  • Once the communication channel is established(in your case i think will be via nfc) between a card and a terminal, there is a set way terminal and card will communicate which you need to read from EMV books 3 with supporting book 4. – Adarsh Nanu Feb 05 '18 at 02:51
  • Can you please tell me exactly? Because I went through that book. But I am not sure what to put exactly. It will be really helpful if you can suggest me any way. – faysal Feb 05 '18 at 03:57
  • check out this link, it can give you a high level understanding of how an emv transaction is. https://www.quora.com/Step-by-step-How-does-a-EMV-contact-card-payment-work . But can i understand why you want to start from beginning eplicitly. Normally it is a new transaction every time the terminal and card comes to contact. – Adarsh Nanu Feb 05 '18 at 06:13

1 Answers1

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You can not do this my friend. There are some predefined steps for an EMV transactions defined by EMV. So to achieve the worldwide interoperability, the card and terminal both must behave in same manner as defined by EMV.

Here your wish is to indicate the terminal to resend the command that you want. Since terminal's flow is as per EMV it can't be done.

So if you want to restart your transaction then you have to physically remove the card from terminal. After power off only, terminal will again follow the same transaction flow. You can not alter the terminal flow by any how. Flow is following :

  1. Application Selection
  2. Initiate Processing Option
  3. Read Application Data
  4. Processing Restriction
  5. Card Holder Verification
  6. Offline Data Authentication
  7. Terminal Risk Management
  8. Terminal Action Analysis
  9. Card Action Analysis 1
  10. Online processing
  11. Card Action Analysis 2
  12. Completion
  13. Issuer Scrip Processing
Gaurav Shukla
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