atecc-ecdh-python - An ECDH Python Example for ATECC608A

This example shows the Elliptic Curve Diffie Hellman key exchange with ephemeral key created on ATECC608A.

Prerequisites

• Debian 10 host
• Raspberry Pi device
  • e.g. Zero
  • Raspberry Pi OS
  • Attached ATECC608A I2C module
    • Personalized, locked and ready to use

Setup

apt update
apt install -y python3 python3-venv build-essentials
python3 -m venv
source venv/bin/activate
pip3 install wheel
pip3 install -r requirements.txt 

ECDH procedure

1. On device: Generate ephemeral key on ATECC608a via python3 genkey_device.py
2. Exchange ec256-device.pub with host
3. On host: Generate ephemeral key using python python3 genkey_host.py
4. Exchange ec256-host.pub with host
5. On device: Derive ec256-device.key via python3 ecdh_device.py
6. On host: Derive ec256-host.key via python3 ecdh_host.py
7. On host: Calculate md5 ec256-host.key
8. On device: Calculate md5 ec256-device.key
9. Compare md5 hashes and see that they match