Crypto: EdDSA

The EdDSA sample shows how to sign and verify messages using the Edwards25519 curve.

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Board target

nRF9161 DK

PCA10153

nrf9161dk

nrf9161dk/nrf9161/ns nrf9161dk/nrf9161

nRF9160 DK

PCA10090

nrf9160dk

nrf9160dk/nrf9160/ns nrf9160dk/nrf9160

nRF54L15 PDK

PCA10156

nrf54l15pdk_nrf54l15

nrf54l15pdk/nrf54l15/cpuapp/ns

nRF54L15 PDK

PCA10156

nrf54l15pdk

nrf54l15pdk/nrf54l15/cpuapp

nRF54H20 DK

PCA10175

nrf54h20dk

nrf54h20dk/nrf54h20/cpuapp

nRF5340 DK

PCA10095

nrf5340dk

nrf5340dk/nrf5340/cpuapp/ns nrf5340dk/nrf5340/cpuapp

nRF52840 DK

PCA10056

nrf52840dk

nrf52840dk/nrf52840

When built for a board target with the */ns variant, 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. A random Elliptic Curve Cryptography (ECC) key pair is generated in the PSA crypto keystore for signing purposes.

    3. The public key of the ECC key pair is exported to the application.

    4. The exported public key is imported into the PSA crypto key storage to be used for verification.

  2. EdDSA signing and verification:

    1. Signing is performed using the private key of the ECC key pair.

    2. The signature is verified using the exported public key.

  3. Cleanup:

    1. The key pair and public key are removed from the PSA crypto keystore.

Building and running

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

When built as firmware image for a board target with the */ns variant, 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.