How InnerLight works

Nothing here is a black box. This page explains exactly what happens in a session, and then exactly how each of our three systems — the sound, the heartbeat reading, and the encryption — actually works, in plain language first and technical detail second.

The experience, step by step

1. A calm space opens

When you arrive, a soft environment is already present — gentle sound and a breathing guide — not something you have to switch on. A slowly expanding and contracting circle paces your breath at about six breaths per minute, the rate best supported in the research for calming the body. You never have to use it; it is simply there.

2. You tell your story, your way

You can type or speak, whichever is easier. InnerLight listens for what you actually mean, reflects it back, and asks one gentle question at a time drawn from what you said — never a wall of forms, never rushed. You decide when you are ready for a response; nothing answers over you.

3. You are met where you are

Using what you tell us — and, if you like, the breathing guide — the calming sound gently shifts to meet the moment and then eases toward calm. We do not use your heart rate to judge how you feel; beats-per-minute is an ambiguous signal, and we would rather listen to you. The aim is to help you feel heard and steadier while you wait.

4. A bridge to real help — only with your consent

When it would help, InnerLight can connect you to real human support — a crisis line, a mobile crisis team, a telehealth provider, legal aid, and in urgent moments the right emergency help. If you choose to share a summary of what you talked about, you review and control it first. Nothing is shared without your say-so.

System one — the sound

In plain terms: InnerLight’s sound is built on a music-therapy method called the Iso-Principle. Instead of jumping straight to the calmest music — which can feel like being told to “just relax” — it starts with sound that matches where you are, so you feel met, and then gradually eases the music toward calm and carries you with it. As the reading of your state changes, the music moves between prepared “lanes” that differ in energy, tempo, and fullness.

Technical detail: lanes are selected from the conversation (and, optionally, the breathing guide) and sequenced by the Iso-Principle — enter on a matching lane, then step down through intermediate lanes to the calmest over one to three minutes. Calming targets follow the literature: slower tempo (roughly a 60–80 bpm feel, or a decreasing tempo, which produced the strongest parasympathetic response in controlled work), low rhythmic density, soft attacks, and minimal sudden dynamics. Transitions use equal-power (cosine) crossfades and gain automation so changes are smooth rather than abrupt. In active development: stem-layered lanes (fading instrument layers in and out instead of switching tracks) and a low-pass “settle” sweep so the sound literally softens as you calm.

Honest limit: calming-audio effects are real but modest and individual, and “60 bpm music syncs your heartbeat” is an overstatement — music nudges the nervous system toward rest; it does not lock your pulse to the beat. Full citations are on the Research & Methods page.

System two — the heartbeat reading

In plain terms: if you allow the camera, InnerLight can estimate your heart rate without touching you, by watching the tiny color changes in your face as blood pulses just beneath the skin. This happens entirely on your own device — the video is analyzed in your browser and is never sent to us or stored. The reading is shown to you, powers an anonymous, words-free view a supporter can watch, and is recorded for research — but we do not treat a higher heart rate as “distress.” Beats-per-minute is too ambiguous for that, so it never decides anything on its own.

Technical detail: this is remote photoplethysmography (rPPG). We sample skin from the forehead and both cheeks (avoiding eyes and mouth, which add motion noise), combine the red, green, and blue channels using the Plane-Orthogonal-to-Skin (POS) algorithm to cancel motion and lighting, band-limit the signal to the plausible heart range (about 0.7–2.8 Hz), and add a sub-harmonic guard so the estimator cannot latch onto half the true rate. In dim light the image is brightened first (adaptive gamma correction) so people in poor lighting are not excluded. Every reading carries a confidence tier — measured, estimated, or baseline-held — so coverage is complete without overstating precision.

Why webcam rPPG and not a wearable: a crisis tool must work for anyone, instantly, with no device to buy or pair. It needs reasonable light and a mostly still face, and we label every reading’s confidence rather than pretend to clinical accuracy. Facial-expression signals use Google’s on-device MediaPipe Face Landmarker. Method citations are on the Research page.

System three — the Axiom Harmony Protocol (our encryption)

In plain terms: if you choose to save your story so you can return to it, InnerLight locks it with a key made from a private return code that only you hold. Through a deliberately slow mathematical process, your code becomes a unique digital key, and your words are locked with it so thoroughly that the stored result looks like random noise. We never keep your code, so we can never unlock your story — and neither can anyone who breaks into the server. If you lose the code, the data is gone for good. That is the trade-off of real privacy: the lock is genuine, and you hold the only key.

Technical detail: AHP encrypts each payload with AES-256-GCM (Advanced Encryption Standard, 256-bit, Galois/Counter Mode) — an authenticated cipher protecting both confidentiality and integrity. The key is derived from the return code with PBKDF2-HMAC-SHA256 at 390,000 iterations and a random salt, a slow key-stretch that makes brute force enormously expensive. Every encryption uses a fresh random nonce, and the protocol version is bound in as authenticated associated data. The key is never written to disk — only ciphertext, salt, and nonce are stored. Toward the operator this is a zero-knowledge design: InnerLight holds bytes it cannot read.

Honest limit: AES-256-GCM with strong key derivation is robust modern cryptography, but it is not yet post-quantum. A documented hardening path is to add a post-quantum key-exchange layer (for example ML-KEM / Kyber) alongside it. We state this openly rather than overstate the protection.

What we never do

InnerLight never diagnoses, never names a clinical condition, never practices medicine or law, and never uses engagement tricks (no streaks, badges, or pressure to stay). The raw conversation is not stored; only a summary you choose to save is kept, with identifying details automatically removed. More on data handling is on the Your privacy page, and our crisis protocol is on the Safety page.

InnerLight is a companion for the wait and a bridge to care. It does not diagnose or treat, and it is not a substitute for professional or emergency help. If you are in immediate danger, call or text 988, or call 911.

← Back to InnerLight