The Signet, a Morse Code Steganography Beacon for Protest Messaging.

What is it?

The Signet is a small, fully assembled, WiFi-configurable beacon that embeds hidden messages into video footage using Morse code transmitted via blinking light. It converts plain text into International Morse Code and signals it through either a visible RGB LED or a discreet 950nm infrared LED — allowing messages to be captured by cameras and decoded later from the recorded video.

Built around the Seeed Studio XIAO ESP32-C6 and housed in a compact, snap-fit 3D-printed enclosure, The Signet is designed to be deployed quickly and discreetly using magnetic mounting. No apps, no accounts, no internet connection required. Just power it on, connect to its WiFi access point from any phone or laptop browser, type your message, and go.

Why does this exist?

In many places around the world, digital censorship and content suppression are escalating. The Signet was built for situations where people need to communicate ideas in public — especially during peaceful demonstrations — without relying on platforms, audio, or live speech. Instead of shouting a message that can be drowned out or provoke confrontation, The Signet lets a message persist inside the footage itself, traveling with every copy of the video. The message is durable: it can be discovered and decoded later by participants, journalists, or anyone reviewing recordings.

How this differs from watermarking?

While The Signet and watermarking both involve embedding information into video, they solve very different problems and operate in fundamentally different ways.

Watermarking

• Added after recording during editing or encoding
• Relies on digital pixel or compression manipulation
• Usually invisible and algorithmic
• Can often be removed or degraded through re-encoding
• Primarily serves ownership and copyright enforcement

The Signet

• Embeds information at the moment of recording
• Uses optical signaling (visible or IR light)
• Independent of codecs, platforms, and formats
• Becomes part of the physical scene, not a digital layer
• Can reveal edits through continuity breaks

Watermarking alters the media, The Signet alters the scene.

Features

Hardware: XIAO ESP32-C6 SoC with dual emitters (RGB LED + 950nm IR LED), 500 mAh LiPo battery with charge protection, USB-C charging (operates while charging), magnetic mounting for fast placement, snap-fit 3D-printed enclosure, and optional belt clip.

Firmware: Plain text to International Morse code conversion, adjustable WPM speed, language-agnostic encoding that works the same worldwide, selectable Visible (RGB) or Discreet (IR) output modes, browser-based WiFi captive portal UI with no app needed, fully offline operation, auto WiFi shutdown after 90 seconds of inactivity, and a "Stateless by Power" design that stores no messages on the device. No telemetry. No accounts.

What's included?

Each unit ships fully assembled and tested, ready to use out of the box. The package includes: The Signet beacon (fully assembled and tested PCB, with battery, in 3D-printed enclosure).

You supply your own phone or laptop to access the configuration interface — no special software needed, no app to install, no account to register... Just a web browser.

Technical Specifications

• Microcontroller: Seeed Studio XIAO ESP32-C6
• Emitters: RGB LED (visible) + 950nm IR LED (discreet)
• Battery: 503035 3.7V 500mAh LiPo with discharge protection
• Charging: USB-C (device operates while charging)
• Configuration: WiFi AP + captive portal, browser-based UI
• Connectivity: None — fully offline by design
• Mounting: Magnetic, optional belt clip/holster
• Enclosure: 3D-printed, snap-fit (2 pieces) ASA
• Firmware: Arduino IDE (ESP32-C6), open source (MIT license), OTA Updates
• Hardware license: CERN-OHL-P 2.0

Who is this for?

The Signet is built for (h)activists, journalists, researchers, and anyone interested in censorship-resistant communication tools. Some familiarity with Morse code concepts is helpful but not required — the device handles all encoding automatically. It also makes a compelling conversation piece and educational tool for anyone interested in steganography, embedded systems, or open-source hardware.

Full documentation, firmware source code, PCB schematics, and 3D print files are available on GitHub: https://github.com/Quiklearner2099/The_Signet