NFC payment demo with Samsung Nexus

Question

I´ve been reading a lot about NFC, card emulation and etc.... I found two very helpful posts about this issue:

Android and Symbian NFC mobile development questions and answers (FAQ)

http://forum.xda-developers.com/showthread.php?t=1281946

Reading them I realized that it is quite complicated to write an application to make a payment.

Since I just want to see "something" working I'd like to ask the more experienced people if using the patch provided at xda-developers forum (second link above) would be enough just to write an appication that would open some door ou register/authorize someone´s entrance at an event (provided that I have a NFC device to properly interact with my phone, of course).

Thank you all

Answer 1

In my opinion, you shouldn't bother with trying the patches on XDA Developers, especially if you are considering using Android 4.0 ICS. Android 4.0 already has built-in functionality on the Nexus S and Galaxy Nexus phones to enable card emulation. Drawback: you need a rooted phone to make it all work (see eg How to obtain NFCEE_ADMIN permission on rooted phone? for an example of someone succeeding).

A perhaps simpler approach is using NFC peer-to-peer communication ("Android Beam") with an external reader. This can work with any Android NFC device using a simple app to push the necessary data to the reader. Provided the reader support peer-to-peer communication, this is far the easiest solution. It would require some development work on the reader side, though, see http://code.google.com/p/ismb-npp-java/wiki/NppFromPhoneToACR122 for an example of this approach.

Answer 2

Payment is mostly impossible since you don't have the keys for the JavaCard card manager, better forget about it. Additionally, to write a Visa, etc compatible payment applet, you need access to their specs, which means signing NDAs, paying money, etc.

Apparently the Mifare chip has stock keys, so you can modify it. So if you have a reader, and a device (door, etc.) that uses Mifare cards, you might be able to get it work. The thread also mentions that you might be able to clone your transport card. But:

• you need to build your own firmware and flash it on a rooted phone
• you may need to port the patches to whatever is the current GB version (2.3.7) or use exactly the same (old) tag
• You need to do a lot more reading :)