Method of conducting a transaction using an NFC device

1. A method of conducting a transaction between a Near Field Communication (NFC) device and a passive contactless integrated circuit, the NFC device comprising an NFC controller coupled to a contactless communication interface, and at least a first host processor comprising at least one card application program, the method comprising:

providing, in an intermediary unit, a first protocol inversion program, wherein the intermediary unit of the NFC device:

sets the contactless communication interface in an active mode wherein the interface emits a magnetic field and establishes a communication with the contactless integrated circuit,

receives, from the contactless integrated circuit, first reader application commands and transferring the first reader application commands to the first host processor, and

receives, from the first host processor, first card application responses and transferring the first card application responses to the contactless integrated circuit;

providing, in the contactless integrated circuit, at least one reader application emulation program configured to supply first reader application commands and to treat first card application responses; and

providing, in the contactless integrated circuit, a second protocol inversion program configured to cooperate with the reader application emulation program;

establishing, between the first and the second inversion programs, a contactless communication wherein the intermediary unit acts as a reader relative to the contactless integrated circuit; and

by an intermediary of the second and the first inversion programs:

transferring to the first host processor, first reader application commands supplied by the reader application emulation program, and

transferring to the reader application emulation program, first card application responses supplied by the card application of the first host processor.

2. The method of claim 1 , further comprising, by the intermediary unit:

receiving from the first host processor, first card application responses, encapsulating the first card application responses in second reader application commands, and transferring the second reader application commands to the contactless integrated circuit; and

receiving from the contactless integrated circuit, first reader application commands encapsulated in second card application responses, de-encapsulating the first reader application commands, and transferring the first reader application commands to the first host processor.

3. The method of claim 2 , wherein the second reader application commands and the second card application responses are in the APDU ISO 7816 format.

4. The method of claim 1 , wherein the first reader application commands emitted by the reader application emulation program and the first card application responses emitted by the card application program are in the Application Protocol Data Unit (APDU) ISO 7816 format.

5. The method of claim 1 , further comprising supplying to the first host processor, by the intermediary unit, Host Controller Interface (HCI) commands that cause the first host processor to perceive that the first reader application commands received from the contactless integrated circuit are emitted by an NFC reader in the active mode.

6. The method of claim 1 , further comprising recording in a registry at the disposal of the first host processor, Radio Frequency (RF) channel parameters that cause the first host processor to perceive that the first reader application commands received from the contactless integrated circuit as having been emitted by an NFC reader in the active mode.

7. The method of claim 1 , wherein the intermediary unit is a host controller of the NFC device.

8. The method of claim 1 , wherein the intermediary unit is a second host processor of the NFC device.