https://devzone.nordicsemi.com/f/nordic-q-a/19131/dfu-signing-encryption-securityI can see in the latest SDK 12.2 that signing of the dfu firmware files is possible. Am I right in thinking that this signing verifies the source of the firmware files and does not encrypt them? And if we want to protect against reverse engineeringen-USTelligent Community 13Mon, 23 Jan 2017 09:41:13 GMThttps://devzone.nordicsemi.com/thread/74039?ContentTypeID=1Mon, 23 Jan 2017 09:41:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:142bb24a-3c35-4088-8ceb-a85226f63bb0bjorn-spockeli<p>You are correct, the signing feature is only used to verify that the firmware image has been generated by a trusted source. The firmware image itself is <strong>not</strong> encrypted and is sent in plain text unless you add additional encryption at the application layer or use the build-in Link Layer encryption of BLE. However, you have to take into account that the image must be sent securely to a mobile device( Android or iOS), so I would recommend the first option as this allows you to implement end-to-end encryption.</p> <p>Best regards</p> <p>Bjørn</p><div style="clear:both;"></div>