https://devzone.nordicsemi.com/f/nordic-q-a/75975/using-secure-dfu-bootloader-and-crypto-in-applicationHello, We are trying to use the Cryptocell as used in example nrf_crypto_aes_cbc_with_padding along with Secure DFU. However, when the application loads the crypto engine no longer works the Cryptocell seems to return only zero&#39;s. Closing and reopeningen-USTelligent Community 13Fri, 04 Jun 2021 11:56:47 GMThttps://devzone.nordicsemi.com/thread/313646?ContentTypeID=1Fri, 04 Jun 2021 11:56:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a3b29b7b-141d-4b1f-9db0-442815353541Einar Thorsrud<p>Hi RJ,</p> [quote user=""]We are trying to use the Cryptocell as used in example nrf_crypto_aes_cbc_with_padding along with Secure DFU.[/quote] <p>There should not be a problem combining CryptoCell and the SoftDevice (and that is done in the BLE examples that use LE Secure Connections), so this should work.</p> [quote user=""]However, when the application loads the crypto engine no longer works the Cryptocell seems to return only zero&#39;s.[/quote] <p>Can you explain in detail which function call you refer to and what (output data I assume) is only zero? Can you also show the code you use in this case and how you reproduce the issue? Please include the sdk_config.h as well so I see how you configured nRF Crypto. Are you using the CryptoCell library with or without interrupts?</p> [quote user=""]Closing and reopening the crypto engine causes a soft device error. Can you please advise on what might be causing this?[/quote] <p>Can you explain with reference to code how you close and open the crypto engine, and which SoftDevice error/assert you get.</p> <p>Einar</p><div style="clear:both;"></div>