LE Secure Connections compatible with Android

[VanNuru]

I have my own BLE application on the nRF52832 with SDK 11 and SD 2.0.0 that communicates to my own android app on a sony xperia z3 compact. The Android version is 6.0.1 and the tech-specs of the xperia say it's bt 4.0 compatible.

I'd like to implement Secure Connections Pairing because LE Legacy Pairing is insecure. As BT 4.2 is supposed to be only a software update from 4.1 and 4.0, I thought it could be possible with my Android version. Unfortunately, I cannot find any notes about any Android version supporting BT 4.2 and if I activate LE Secure Connections in my nRF, the pairing does not work.

Has anybody succeeded trying to implement LE Secure Connections for communication with an Android device?

[Hung Bui]

LESC is supported on our test Sony Z3 compact Android 6.0.1

What is the issue with yours ?

Note that if you are testing with the example ble_app_multirole_lesc, you would need to press button 1 when pairing. It's using Numeric confirmation as the MITM mechanism. You need to use UART to get the prompt.

Also if you are bonding using the Bluetooth Setting, the phone disconnect automatically right after bond process. If you want to keep the connection, please use an app, nRF Connect for example.

[VanNuru]

I'm not quite sure what the problem is. I hope to be able to do some tests in the next few days with your example programms. But I'll have to modify them anyway, because we have custom hardware with no real i/o capacity, which is why I'm using a static passkey. Or maybe, I'll just output the comparison numbers to the terminal. I'll come back, when I know more. Thanks so far.

[Hung Bui]

ok, just be aware of issue #5 in New Found issues section here.

[VanNuru]

ah, thx. But does it also apply sdk11, which is what I'm using? And doesn't passkey entry use another key exchange protocoll that just works and numeric comparison?

[Hung Bui]

yes it's applied for SDK v11 also. And yes, passkey exchange is different from numeric comparison and just work. I linked just in case you use just work. Note that using static passkey is not covered by spec and reduces the security level of the whole pairing process.

[VanNuru]

ok, thank you. I know that static passkey is not optimal, but without i/o capabilities, there is no alternative but oob with nfc, which we also cannot use. So we prefer at least a bit of mitm protection and recommend pairing in a safe environment instead of just works.