what code is returned when a bonded peripheral does not respond to s120 Central sending Start Encryption Response

[mrowe]

The S120 Central after scanning, connecting, and issues a sd_ble_gap_encrypt() to secure the link.  If the peripheral's bond (LTK) is corrupted or incorrect, the sniffer shows that the peripheral never replies to the Central send of a Start Encryption Response message.

What does the soft device return in this case.

I need to know this because we want to delete the bond whenever this happens.  It is not clear how the application will know that this actually occurred (periph has bad bond info).

[FormerMember]

The message sequence chart "GAP Central Encryption Establishment using stored keys", variant #3, shows that the central (s120) will disconnect the link when the peripheral has wrong keys. The application will receive the event BLE_GAP_EVT_DISCONNECTED.