Rún

Rún is a secure messenger built for people who refuse to compromise on privacy. Every message is end-to-end encrypted before it leaves your device. No server, no company, and no government can
read your conversations.

Rún requires no account, no phone number, and no email address. There is nothing to link back to your identity. Contacts are added in person by scanning QR codes, or through a vouched
introduction from someone you already trust — no central directory, no contact discovery, no social graph.

All traffic is routed through the Tor network, hiding your IP address and location even from Rún's own relay. An observer monitoring your network sees only encrypted Tor traffic — they cannot
tell who you are talking to or what you are saying. Messages are padded to fixed sizes, so not even the length of a message leaks.

Messages live in memory only — they are never written to disk. Leave a chat or close the app, and they are gone. There is no message history to scroll through, no archive to subpoena, and no
backup to leak. The relay stores only temporary encrypted blobs it cannot read, in inboxes that expire on their own.

Your vault is encrypted at rest with AES-256 via SQLCipher, its key derived with Argon2id and backed by the Android Keystore. You choose how hard it is to reach:

• Casual — quick PIN unlock, with relaxed auto-lock and self-wipe timers.
• Private — the vault key is also bound to the phone's security chip, behind your fingerprint, face, or device passcode. A seized phone strongly resists offline attacks.
• Maximum — the PIN is replaced by a strong passphrase and the timers are at their tightest. Even a fully imaged phone stays shut.

At every level Rún locks itself when idle, wipes after too many wrong unlock attempts, and self-destructs after a long stretch of inactivity — how strict is set by the level you choose. A wipe
erases the encryption keys themselves, leaving nothing recoverable.

Group chats live only on their members' phones. Every group message is sent privately to each member — on the wire it is indistinguishable from a one-to-one chat, so no one watching can tell a
group exists.

No analytics. No tracking. No advertising. No crash reporting. No cloud backups. No push notifications — they would route through Google and reveal that a message arrived, and when. Rún never
phones home; you see your messages when you open the app.

Rún is built for journalists, activists, whistleblowers, and anyone who believes private conversation is a fundamental right.

Key features:
- End-to-end encryption with forward secrecy (AES-256-GCM + Double Ratchet)
- No account, phone number, or email required
- In-person QR contact exchange and vouched introductions
- Group chats that are invisible on the wire
- Messages held in memory only — never stored on disk
- Encrypted local vault (SQLCipher, Argon2id, Android Keystore)
- Three protection levels: Casual, Private, Maximum
- Hardware-bound vault key behind biometrics (Private)
- Passphrase instead of PIN (Maximum)
- Auto-lock, wipe on repeated wrong attempts, self-destruct on inactivity
- Message padding hides even message sizes
- Screenshots blocked
- No analytics, tracking, ads, or crash reporting
- No cloud backups — your data never leaves your device