Heart Codec turns the subtle skin-color changes caused by your heartbeat into a covert communication channel. Record a video, encode a secret message into your forehead pixels, and decode it later — all entirely in your browser.
How it works in 4 steps
Film your face for a few seconds using your webcam
The rPPG algorithm extracts the cardiac signal from the pixels
A secret message is modulated into the pulse frequency
The message is recovered through spectral analysis of the video
Features
The full codebase is available on GitHub. Inspect, fork, and contribute freely.
The injected signal amplitude (~10/255) is invisible to the naked eye. The video looks unchanged.
Decoding uses the FFT to identify the carrier frequencies (5 Hz and 8 Hz) for each bit.
A fun proof-of-concept at the intersection of signal processing, computer vision, and steganography.
⚠️ This is a toy project — do not use for real encryption or to protect sensitive data.