https://devzone.nordicsemi.com/f/nordic-q-a/62063/nrf-dfuHii, I am trying to flash secure_bootloader into my nRF 52 SDK. I am facing some issue. can you please explain how to create &quot;micro_ecc_lib_nrf52.a&quot; file (which software) I got below error [ cannot find ../../../../../external/micro-ecc/nrf52hf_armgccen-USTelligent Community 13Tue, 02 Jun 2020 14:46:45 GMThttps://devzone.nordicsemi.com/thread/252794?ContentTypeID=1Tue, 02 Jun 2020 14:46:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e7f8828f-256f-4cb7-b62c-35d7c1f5d44aVojislav<p>Once the GCC compiler, git, and make are in place, we can use a shortcut provided within the SDK to do the rest of the work for us. Open a Command window and navigate to the directory C:\u-blox\nRF5_SDK_16.0.0_98a08e2\external\micro-ecc There you will find a batch file (and a script for macOS and Linux) called &quot;build_all&quot;. Go ahead and run that to download micro-ecc and build.<br />At this point, the SDK has the necessary encryption libraries not only for DFU use, but also for establishing secure connections through pairing and bonding.<br /><br />Also, you can find nordic explanation in the infocenter:&nbsp;<a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Flib_crypto_backend_micro_ecc.html">https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Flib_crypto_backend_micro_ecc.html<br /><br /></a></p> <p>Best regards,<br />Vojislav</p><div style="clear:both;"></div>