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.

Overview

The sample follows these steps to perform an ECDH key exchange:

  1. First, the sample performs 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. Then, ECDH key exchange is performed using the generated key pairs.

  3. Afterwards, the sample performs cleanup:

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

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Build target

nRF5340 DK

PCA10095

nrf5340dk_nrf5340

nrf5340dk_nrf5340_cpuapp_ns

nRF5340 DK

PCA10095

nrf5340dk_nrf5340

nrf5340dk_nrf5340_cpuapp

nRF9160 DK

PCA10090

nrf9160dk_nrf9160

nrf9160dk_nrf9160_ns

nRF9160 DK

PCA10090

nrf9160dk_nrf9160

nrf9160dk_nrf9160

nRF52840 DK

PCA10056

nrf52840dk_nrf52840

nrf52840dk_nrf52840

When built for nrf5340dk_nrf5340_cpuapp_ns and nrf9160dk_nrf9160_ns targets, the sample is configured to compile and run as a non-secure application. Therefore, it automatically includes TF-M that prepares the required peripherals to be available for the application.

Building and running

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

See Building and programming an application for information about how to build and program the application.

Testing

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

  1. Connect to the kit with a terminal emulator (for example, PuTTY). See How to connect with PuTTY for the required settings.

  2. Compile and program the application.

  3. Observe the logs from the application using an RTT Viewer or a terminal emulator.

Note

By default, the sample is configured to use both RTT and UART for logging. If you are using RTT, skip the first step of the testing procedure.