https://devzone.nordicsemi.com/f/nordic-q-a/75894/ble-security-mode-2-level-1-unauthenticated-pairing-with-data-signingHello, we are developing a verry small sensor node. Since we like to know if the sensor we are connected to, is one of our sensors instead of an attacker fake sensor we need a method to check this. Because the sensor node is so small (3mm x 27mm) ween-USTelligent Community 13Wed, 02 Jun 2021 12:46:05 GMThttps://devzone.nordicsemi.com/thread/313113?ContentTypeID=1Wed, 02 Jun 2021 12:46:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5b8aadd2-f068-41b7-9777-0a2cf3a5b6f4Hung Bui<p>Hi Dominik,&nbsp;</p> <p></p> <p>Data signing is not supported by the softdevice. I don&#39;t think many phones on the market support this feature also.&nbsp;</p> <p>What you can do is either encrypt your data using your own key on application level. There is a discussion about that <a href="https://devzone.nordicsemi.com/f/nordic-q-a/2965/ble-preshared-pin-key-auth">here</a>, it&#39;s pretty old but should give you some idea.&nbsp;</p> <p>Another option is to use some challenge response authentication:&nbsp;<a href="https://en.wikipedia.org/wiki/Challenge%E2%80%93response_authentication">https://en.wikipedia.org/wiki/Challenge%E2%80%93response_authentication</a></p> <p>You can disable the functionality on the central side and disconnect if you don&#39;t receive a correct response to your random generated challenge.&nbsp;</p><div style="clear:both;"></div>