Radioactive Decay Powers Open-Source Bitcoin Seed Generator

An open-source hardware project called Entropy32 Plus has emerged using radioactive decay as a physical entropy source to generate Bitcoin BIP39 seed phrases. The device captures decay events with a Geiger counter, whose timing is then processed through SHA-256 conditioning before mapping it to the BIP39 wordlist.

The core idea behind this project is physical unpredictability, which radioactivity provides in abundance. Individual decay events occur at quantum-mechanically random intervals that cannot be predicted in advance.

A custom PCB built around an ATmega328P microcontroller powers the device, pairing with a small OLED display and a button-driven interface for on-device operation. No software beyond the onboard firmware is required to generate or view a completed seed phrase.