You can enable the Nordic Security Module using PSA crypto support or Legacy crypto support.

PSA crypto support

To enable the Nordic Security Module with PSA crypto support, set the CONFIG_NRF_SECURITY Kconfig option along with additional configuration options, as described in Driver configurations and supported features.

PSA crypto support is provided through PSA Crypto APIs and is implemented by PSA core. PSA core uses PSA drivers to implement the cryptographic features either in software, or using hardware accelerators.

Starting from nRF Connect SDK v2.4.0, the Mbed TLS PSA core is deprecated and replaced with nrf_oberon PSA core. The nrf_oberon PSA core code is an optimized and efficient implementation of PSA core licensed for use on Nordic Semiconductor devices.

PSA core

Configuration option





Mbed TLS



Legacy crypto support

To enable the legacy crypto support mode of Nordic Security Module, set the CONFIG_NORDIC_SECURITY_BACKEND Kconfig option along with additional configuration options, as described in Legacy configurations and supported features. The legacy crypto support allows backwards compatibility for software that requires usage of Mbed TLS crypto toolbox functions prefixed with mbedtls_.

Custom Mbed TLS configuration files

The Nordic Security Module (nrf_security) Kconfig options are used to generate an Mbed TLS configuration file.

Although not recommended, it is possible to provide a custom Mbed TLS configuration file by disabling CONFIG_GENERATE_MBEDTLS_CFG_FILE. See User-provided Mbed TLS config header.

Building with TF-M

If CONFIG_BUILD_WITH_TFM is enabled together with CONFIG_NRF_SECURITY, the TF-M secure image will enable the use of the hardware acceleration of Arm CryptoCell. In this case, the Kconfig configurations in the Nordic Security Module control the features enabled in TF-M.