Crypto: ECDH

The ECDH sample shows how to perform an Elliptic-curve Diffie–Hellman key exchange to allow two parties to obtain a shared secret.

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Build target

nRF9161 DK

PCA10153

nrf9161dk_nrf9161

nrf9161dk_nrf9161_ns nrf9161dk_nrf9161

nRF9160 DK

PCA10090

nrf9160dk_nrf9160

nrf9160dk_nrf9160_ns nrf9160dk_nrf9160

nRF54L15 PDK

nrf54l15pdk_nrf54l15_cpuapp

nrf54l15pdk_nrf54l15_cpuapp_ns nrf54l15pdk_nrf54l15_cpuapp

nRF54H20 DK

PCA10175

nrf54h20dk_nrf54h20_cpuapp

nrf54h20dk_nrf54h20_cpuapp

nRF5340 DK

PCA10095

nrf5340dk_nrf5340

nrf5340dk_nrf5340_cpuapp_ns nrf5340dk_nrf5340_cpuapp

nRF52840 DK

PCA10056

nrf52840dk_nrf52840

nrf52840dk_nrf52840

When built for an _ns build target, the sample is configured to compile and run as a non-secure application with Cortex-M Security Extensions enabled. Therefore, it automatically includes Trusted Firmware-M that prepares the required peripherals and secure services to be available for the application.

Overview

The sample performs the following operations:

  1. Initialization:

    1. The Platform Security Architecture (PSA) API is initialized.

    2. Two random Elliptic Curve Cryptography (ECC) key pairs are generated and imported into the PSA crypto keystore.

  2. ECDH key exchange using the generated key pairs.

  3. Cleanup:

    1. The key pairs are removed from the PSA crypto keystore.

Building and running

This sample can be found under samples/crypto/ecdh in the nRF Connect SDK folder structure.

When built as firmware image for the _ns build target, the sample has Cortex-M Security Extensions (CMSE) enabled and separates the firmware between Non-Secure Processing Environment (NSPE) and Secure Processing Environment (SPE). Because of this, it automatically includes the Trusted Firmware-M (TF-M). To read more about CMSE, see Processing environments.

To build the sample with Visual Studio Code, follow the steps listed on the How to build an application page in the nRF Connect for VS Code extension documentation. See Configuring and building an application for other building scenarios, Programming an application for programming steps, and Testing and optimization for general information about testing and debugging in the nRF Connect SDK.

Testing

After programming the sample to your development kit, complete the following steps to test it:

  1. Connect to the kit with a terminal emulator (for example, nRF Connect Serial Terminal). See Testing and optimization for the required settings and steps.

  2. Compile and program the application.

  3. Observe the logs from the application using a terminal emulator.