https://devzone.nordicsemi.com/f/nordic-q-a/27477/ble-bootloaaderi used pca10040_debug of bootloader_secure of nRF5_SDK_14.1.0_1dda907. i created the key by myself. Bootloader and zip file used the same key. My device is in DfuTarg mode. But send the zip is not successful. Debug : uesd break point. en-USTelligent Community 13Thu, 23 Nov 2017 00:19:37 GMThttps://devzone.nordicsemi.com/thread/108531?ContentTypeID=1Thu, 23 Nov 2017 00:19:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4b6f2038-5df6-4294-8b32-06e149f84fe9Woody Hung<p>Excuse me!</p> <p>I used the command: nrfutil.exe pkg generate --key-file %KeyFile% --application %BinFile% --application-version 0x01 --hw-version 52 --sd-req 0x90 %ZipFile%</p> <p>0x90 : The number and my softdevice firmware ID is different, then lead to fail.</p> <p>So i used the same id, it is successful.</p> <p>thx</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/108530?ContentTypeID=1Wed, 22 Nov 2017 16:27:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9c3d0023-c8c0-4617-b9f4-fd4530ae9ae9Hung Bui<p>How did you create the keys ? Did you use nrfutil to create ? What is the command_offset and command_size you have there ?</p><div style="clear:both;"></div>