https://devzone.nordicsemi.com/f/nordic-q-a/44019/dfu-crc-problemHi, I have to modify DFU to support AES encrypted image. I modified nrfutil, file package.py, After line bin_length = int(Package.calculate_file_size(bin_file_path)) (approx ilne no. 410 - 420) I encrypted contents of bin_file_path (firmware imageen-USTelligent Community 13Fri, 22 Feb 2019 14:54:22 GMThttps://devzone.nordicsemi.com/thread/172547?ContentTypeID=1Fri, 22 Feb 2019 14:54:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7a5aa465-764c-4bdf-b32e-281379ffa9c8gaminn<p>Sorry, I didn&#39;t see this post before. The fix was to calculate crc before encryption, not after.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/172511?ContentTypeID=1Fri, 22 Feb 2019 13:24:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:62f5c05c-188b-4887-8251-e671a1965ae5Einar Thorsrud<p>Hi,</p> <p><a href="https://devzone.nordicsemi.com/f/nordic-q-a/37260/adding-encryption-to-secure-dfu-sdk-v15">This excellent post</a> describes all the steps you need to take to add firmware encryption of DFU images.</p><div style="clear:both;"></div>