https://devzone.nordicsemi.com/f/nordic-q-a/55957/gazell---bidirectional-comms-with-encrypted-pipeHello, I am currently working on a project that involves the host device to send configurations parameters over to the device. I was hoping the connection between in device and host to be encrypted as there could be multiple hosts/devices in the vicinityen-USTelligent Community 13Fri, 27 Dec 2019 16:50:04 GMThttps://devzone.nordicsemi.com/thread/226962?ContentTypeID=1Fri, 27 Dec 2019 16:50:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2e268a20-698f-428a-8d76-a7790bd72f54mmak<p>Alright thanks for the confirmation and advice!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/226951?ContentTypeID=1Fri, 27 Dec 2019 15:22:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f767e35b-6ae3-45f9-88e2-91e90f7ceb8bHung Bui<p>Hi Mmak,</p> <p>Our expert in Gazell is current on holiday and will be back on 2nd week of January. I will try to help you in the mean time.&nbsp;<br />As you can find in&nbsp;gzp_process_encrypted_user_data() function in nrf_gzp_host.c, the ACK packet is automatically built with only the encrypted validation ID and session counter number.&nbsp;</p> <p>You would need to use non encrypted pipe for piggy packing data back from host to device.</p> <p><br />However, I do think that it&#39;s possible to modify the function&nbsp;<span>gzp_process_encrypted_user_data() to add your custom data in. And you need to modify the&nbsp;gzp_crypt_tx_transaction() function in nrf_gzp_device.c to extract the user data out on the device side. I haven&#39;t&nbsp;tested this though.&nbsp;</span></p><div style="clear:both;"></div>