Can you provide sample program for security manager keypress notification?

[Sash]

Can you please provide security manager keypress notification sample program for bot peripheral and central program. I want to know why it is used and what is the main purpose of using that. I read bluetooth specification but i don't have clear idea about that topic.

[Kenneth]

I don't have any short introduction of BLE security, hopefully a google search on BLE security may be of help if you are interested, such as these results: 
https://stackoverflow.com/questions/38963836/bluetooth-low-energy-gatt-security-levels 
https://devzone.nordicsemi.com/f/nordic-q-a/35856/questions-about-lesc-mitm-and-passkey 
https://security.stackexchange.com/questions/190575/ble-4-2-le-secure-connection 

You should find examples in our nRF5 SDK that show various implementation of the above security modes and levels.

For instance I have shown a way you can find examples that support LE secure connection (or not) here:
https://devzone.nordicsemi.com/f/nordic-q-a/47518/secure-connections-with-no-keyboard-and-no-display/223238#223238 

A good start if you are interested in LE secure connection may be to use:
\ble_central\ble_app_hrs_c\
\ble_peripheral\ble_app_hrs\