https://devzone.nordicsemi.com/f/nordic-q-a/83540/ble-encryption-with-zephyrHi, I&#39;m using nRF Connect SDK v1.7.1 with two nrf5430 DK. My goal is to evaluate the different security levels. For testing i send messages with the Nordic Uart service between those two boards. I used bt_conn_set_security() to increase the securityen-USTelligent Community 13Tue, 11 Jan 2022 14:36:53 GMThttps://devzone.nordicsemi.com/thread/347208?ContentTypeID=1Tue, 11 Jan 2022 14:36:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4c961557-16e8-42cf-9f79-da2bbe34266bEdvin<p>Hello,</p> <p>That is correct. It is not the individual messages that are encrypted, but the entire connection. So if you encrypt the link/connection, then all messages are &quot;automatically&quot; encrypted. The reason you can&#39;t see where this encryption happens is because it is done in the Softdevice Controller (in the Link Layer), which is not open source.</p> <p>I am not sure about the details, but perhaps the Softdevice Controller uses&nbsp;<span>bt_ccm_encrypt(), or something similar, but I haven&#39;t seen the source code.&nbsp;</span></p> <p><span></span></p> <p><span>Best regards,</span></p> <p><span>Edvin</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/347192?ContentTypeID=1Tue, 11 Jan 2022 14:06:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e7a4b8ef-9c41-4fbc-9299-0efb383f04deEarthworn<p>So i used a Sniffer. Encryption works with only using bt_conn_set_security(). Still confused about Data Signing</p><div style="clear:both;"></div>