Generator of "Passkey" in "LE Secure Connections"

RE: Generator of "Passkey" in "LE Secure Connections"

takashina hiroki — Wed, 17 Jul 2019 23:34:50 GMT

Thank you for answering.
I understood that.

RE: Generator of "Passkey" in "LE Secure Connections"

AndreasF — Fri, 12 Jul 2019 12:01:40 GMT

Hi.

The passkey is RNG from the SoftDevice.

Which device, central or peripheral, that generates it depends on which side is input / displaying the passkey.

Usually the peripheral is displaying the passkey and the central is inputting the passkey.

Edit: If you have any other questions please create a new ticket, I'm going on holiday :-)

Best regards,

Andreas

RE: Generator of "Passkey" in "LE Secure Connections"

takashina hiroki — Fri, 12 Jul 2019 07:26:21 GMT

Excuse me, it seems that my explanation was bad.

"Passkey" is a recognition that is randomly generated, but I want to know who is generating this random number ("central" or "peripheral").

For example, in the case of "Numeric Comparison", both display the same random number.
I think that it does not match when generating random numbers respectively on both devices.
Therefore, I think that they share the "passkey" generated by either "central" or "peripheral".

RE: Generator of "Passkey" in "LE Secure Connections"

AndreasF — Fri, 12 Jul 2019 06:45:31 GMT

Hi.

Can you take a look at this message sequence chart: Bonding: Passkey Entry: Central Displays.

You get the event BLE_GAP_EVT_PASSKEY_DISPLAY after sd_ble_Gap_sec_params_reply() returns NRF_SUCCESS.

For the input, please look at this message sequence chart: Bonding: Passkey Entry: User Inputs on Central.

The passkey is given as input in when the App receives the BLE_GAP_EVT_AUTH_KEY_REQUEST event.

Best regards,

Andreas