classified
Send a note or a file that encrypts in your browser, opens once, and leaves no readable copy behind - on our servers, in our logs, or in anyone's training data.
Free to use without an account. Optional free and paid accounts raise your monthly sharing allowance.
Open classified ↗What it does
- Encrypts your note or file in the browser with AES-256-GCM before anything is uploaded.
- Puts the decryption key in the link's URL fragment, which browsers never send to a server - so we hold only an unreadable blob.
- Self-destructs on first view or download, and auto-expires at the TTL you choose.
- Optional password mode, where the key is derived from a password inside your browser instead.
The long version is in our how-it-works and FAQ, and the underlying ideas are explained from scratch in the guides library.
Technical documentation
The app publishes its own engineering documentation, written against the shipped implementation rather than summarised from it:
- Security model ↗ Every cryptographic parameter in the v1 scheme, what the server can still observe, and the three limits the design does not solve.
- Request flow ↗ The two API calls behind a share, the enforced size and TTL limits, how expiry actually behaves, and the known failure modes.
- When to use it ↗ Worked handoffs, the constraints that decide the answer, and the four cases where a password manager or document service is the better tool.
Legal and support
- Privacy Policy Zero-knowledge architecture, accounts and sign-in, Paddle billing data, advertising and consent, retention, and your GDPR rights.
- Terms of Service Accounts, free and paid plans, acceptable use, no-warranty terms, and Estonian governing law.
- Refund Policy Auto-renewal, cancellation, plan changes, and how refunds are handled by Paddle as Merchant of Record.
Questions about classified? Reach us via the contact address on our contact page.