Nostr Signing Device (NSD)
Bonus Project
This guide is a bonus project for Bitcoiners interested in Nostr. The same security principles that apply to Bitcoin private keys - keeping them offline and isolated - apply to your Nostr identity.
What You'll Do
In this guide, you will:
- Set up Arduino IDE for ESP32 development
- Flash firmware to a LILYGO T-Display
- Install the Horse browser extension
- Connect to Nostr clients securely
Time required: 1-2 hours
Difficulty: Intermediate
Estimated cost: $10-15 (LILYGO T-Display)
Prerequisites: LILYGO T-Display, USB cable, Chrome-based browser
Why Use a Hardware Signing Device?​
A Nostr Signing Device (NSD) keeps your private key isolated from your computer:
| Without NSD | With NSD |
|---|---|
| Private key stored in browser/software | Private key stored on hardware device |
| Exposed to malware, keyloggers | Isolated from computer threats |
| Key could be extracted | Key never leaves device |
The NSD signs messages directly on the device - your private key never touches your computer.
How It Works​
NSD (signs messages) --> Horse Extension --> Nostr Client
Components:
- LILYGO T-Display - The physical signing device
- Horse Extension - Browser extension that connects NSD to clients
- Nostr Client - Where you interact with Nostr (e.g., Coracle)
What You'll Need​
| Component | Description | Source |
|---|---|---|
| LILYGO T-Display 1.14 | The signing hardware | AliExpress |
| USB Cable | To connect and flash | Usually included |
| Arduino IDE | To build and upload firmware | Free download |
| Horse Extension | Browser bridge | Chrome Web Store |
Let's proceed with the setup.