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?

[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.

[jemajuca]

Hi Hung. I think most of us are confused by the use of 4.2 features because of this diversity of posibilities on Android devices. Can you post the BLE 4.2 compatible Android devices you have tested? Also, has Nordic any test app for check the different smartphones compatibility? Thank you.

[Hung Bui]

@jemajuca: A phone doesn't need to support LE Secure Connection to be 4.2 compatible. As far as I understand LE Secure Connection is optional feature.

We unfortunately don't have a list of phone that support LE Secure connection. As far as I know newer Nexus phones and Samsung from S6 support it.