What mechanism randomizes the BLE address that gets hashed with the IRK?

[Anders Nelson]

I can't seem to find where/how the BLE address gets randomized so it changes periodically when using the BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE address type.

-It seems trivial to manually change the address but how about the hashing of this address with the IRK?

-Is this mechanism exposed outside the softdevice?

-Does the softdevice support this address type?

Thanks!

[Hung Bui]

Hi Anders,

The S110 currently use BLE_GAP_ADDR_TYPE_RANDOM_STATIC address type.

EDITED: the following information provided earlier was not correct.

[u] As you know you can set BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE type in sd_ble_gap_address_set()

The current S110 stack provides no API to generate address from IRK, and you would need to do that by your application. You can have a look at section 10.8.2.2 at Part C, Vol 3 in the Bluetooth Core Spec v4.0 to know how to generate the random resolvable address from IRK.[/u]

Corrected information:

Current S110 softdevice (v6.x and v7.0.0 alpha) doesn't have a way to distribute the IRK when bonding. Therefore BLE_GAP_ADDR_TYPE_RANDOM_PRIVATE_RESOLVABLE is not usable with the current S110 softdevice.

This may change in S110 v7.x, but I can't say for sure when it will be available.

I am sorry for the confusion.

[Matt-M]

Dear Hung Bui,

We are also interested in this function for our projects using nRF51822. Do you have any update for S110 version?

"This may change in S110 v7.x, but I can't say for sure when it will be available."

Best Regards, Matt

[Hung Bui]

Hi Matt, It's is supported on S110 v7.0 production. You can have a look at the release note to find more information. Please note that to add the custom IRK in you would need to use the sd_ble_opt_set API.