NFC pairing - what is OOB data

[Matthew K]

Hi guys. When reading the OOB pairing example,

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/peripheral_nfc_pairing/README.html

"This sample can exchange OOB data with an NFC Forum Polling device"

I'm having trouble understanding this example.

What exactly is this "OOB data"? Like Long Term Key (LTK), IRK, ERK are the OOB data?

My smartphone is Galaxy S20 (Android 12) so the LE Secure Connection pairing/bonding should be supported.

Eventually, I want the nRF52840 to bond with my Android phone using NFC/OOB.

I'm using nRF52840 DK. What peripheral SoftDevice function is called that uses this OOB data?

Also, does this SoftDevice function have to be called before the connection with the BLE central device?

Thanks for your help!

[Simonr]

Hi

The OOB data is described in the Bluetooth LE OOB records here. The OOB data is set in the lesc_oob_data_set() function. Is there a specific function you're looking for, they can all be found in the peripheral NFC pairing C:\...\ncs\v2.0.0\nrf\samples\bluetooth\peripheral_nfc_pairing.

Best regards,

Simon

[Matthew K]

Thank you Simon. I want to test the LE Secure Connections pairing with OOB data

[Q] When I click that "NFC forum document" link or the "Bluetooth Secure Simple Pairing Using NFC" link, I only see the NFC's main webpage.
Can I request the document URLs?

[Q] About the OOB data / LE OOB record / BLE pairing messages / LESC OOB data,
infocenter.nordicsemi.com/.../nfc_ndef_ble_pair_message_module_dox.html

Are these defined by the NFC forum or defined by Nordic's nRF5 SDK?

[Q] When tagging the peripheral_nfc_pairing example to an Android phone, does the nRF Connect mobile app has to be running?
Or is this a native Android feature where the Android app sends the "OOB data" without any mobile app running?

[Simonr]

Hi

1. True, it seems the NFC forum has changed and now the specification must be purchased from them it seems. Here is more information on that. I will notify our documentation team that the link must be updated. Thank you for letting us know.

2.This is defined by the NFC and BLE specifications, not by our SDK.

3. It should not be necessary to use the nRF Connect Mobile app to do OOB as this is part of the NFC and BLE spec. and as long as the phone you're using supports BLE and NFC that should be covered in the Android stack.

Best regards,

Simon

[Matthew K]

Thanks Simon. There are several NFC documents shown on the core-specification page.

I don't want to buy every NFC doc. Which one should I refer to?
Data Exchange Format (NDEF) Technical Specification
Connection Handover Technical Specification
Bluetooth Secure Simple Pairing
?

Thank you!

[Simonr]

Hi

Seems like Bluetooth Secure Simple Pairing is the go-to for information on the OOB pairing and BLE compatibility.

Best regards,

Simon