https://devzone.nordicsemi.com/f/nordic-q-a/65880/is-it-possible-to-replace-a-firmware-that-uses-otaI bought a wristband that enables firmware upgrade via OTA. I want to replace its firmware with my own but I don&#39;t have the keys related to the DFU. All I know is that it was using SDK 15.3 Is it possible to replace the firmware with my own - ifen-USTelligent Community 13Mon, 14 Sep 2020 07:21:00 GMThttps://devzone.nordicsemi.com/thread/269290?ContentTypeID=1Mon, 14 Sep 2020 07:21:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6cc324c3-49b1-468e-b82d-0cfc83a0f089Vidar Berg<p>Hello,</p> <p>It will not be possible to do OTA if they require signed updates, unfortunately. You can read more about this verification mechansim here: <span><a title="Signature verification" href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.0.0/lib_bootloader_dfu_validation.html?cp=7_1_3_5_1_1_2_3#lib_bootloader_signatures">Signature verification</a></span></p><div style="clear:both;"></div>