Zero-Knowledge Architecture
Wispr is built on a single, uncompromising principle: we cannot read your data. Not because of a policy — because of math.
Our Mission
Permanence is a bug,
not a feature.
Every email you send, every message you type, every file you share — all of it accumulates in someone else's database, indefinitely. That accumulation creates risk: for breaches, subpoenas, leaks, and surveillance. Wispr exists because some things should disappear.
We built Wispr to be the tool we wished existed — a zero-friction, zero-knowledge secret sharing service where the engineering enforces privacy rather than promising it. No accounts. No tracking. No way for us to betray your trust even if we wanted to.
How It Works
Four guarantees. No exceptions.
Client-Side Encryption
Your browser generates a random AES-256-GCM key using the Web Crypto API. The secret is encrypted locally before any network request is made. Only encrypted ciphertext and an IV are sent to our servers — both are useless without the key.
Key Distribution via URL Fragment
The encryption key lives in the URL fragment — the part after the # symbol. Web standards guarantee that fragments are never sent in HTTP requests. They don't appear in server logs, access logs, or referer headers. We structurally cannot intercept them.
Password Key Wrapping
If you set a password, we use PBKDF2 (100,000 iterations, SHA-256) to derive a wrapping key from that password inside your browser. The AES key is wrapped with AES-KW and sent to the server. The password and unwrapped key never leave your device.
Server-Enforced Burn
Burn-after-reading is enforced with a hard database DELETE on the first reveal — not a flag, not a soft-delete. The row is gone before the response is sent. Even if an attacker copies the link, opening it first means the intended recipient sees nothing.
What we see vs. what you see
What Our Server Sees
{
"id": "sec_8f92j...",
"ciphertext": "U2FsdGVkX1+...",
"iv": "8f3j29d...",
"burnAfterReading": true,
"expiresAt": "2026-12-31T23:59:59Z"
}Random noise. Mathematically impossible to decrypt without the key.
What You See
{
"decrypted": "Meet me at the location.",
"status": "Verified ✓",
"key_source": "URL Fragment",
"burned": true
}The secret, decrypted locally in your browser. Never touches our servers in plaintext.
What We Stand For
Principles we don't negotiate.
Radical Transparency
Our security architecture is fully documented. Our code is open-source. We don't hide behind "trust us" — we show you exactly how it works so you can verify every claim yourself.
No Dark Patterns
No deceptive defaults. No opt-out checkboxes. No 'free trial' to paid subscriptions. No dark UI that nudges you toward giving up more data. The product does exactly what it says.
Universal Access
Wispr works over Tor, VPNs, and privacy-focused browsers without degradation. We don't block unusual IPs or demand you prove you're human. Anonymity tools should work with anonymity tools.
Privacy by Default
You don't have to opt in to privacy — it's the only mode. There's no 'standard' tier that logs more. Every secret gets the same zero-knowledge treatment, no matter what.
No Accounts. Ever.
Creating a secret requires nothing from you — no email, no phone number, no name. There's nothing to compromise, nothing to subpoena, nothing to link back to you.
Open Source
Every line of cryptographic code is auditable. We believe that security through obscurity is not security at all. Read the code, fork it, host it yourself.
The Story
How we got here.
The problem becomes obvious
Every existing tool for sharing sensitive information — passwords, credentials, private notes, confidential files — required trusting a third party. Emailing passwords was common. Slack DMs were permanent. Nothing truly disappeared.
First working prototype
A weekend experiment: AES-256-GCM in the browser, key in the URL fragment, auto-delete on access. The architecture was simple. The implications were significant. The server genuinely could not read what it stored.
Wispr launches publicly
Full open-source release with password protection via PBKDF2/AES-KW, expiry timers, max-view limits, file support, and QR code sharing. Zero-knowledge by design, with every claim documented and auditable.
Fully open-source
Every line of Wispr — from the Web Crypto calls to the Express routes to the database schema — is public. Read the code, audit the cryptography, run your own instance. Trust should be earned, not assumed.
Ready to try it?
CREATE A SECRET