dur.io · Русский (full version)

End-to-end encryption (beta)

Beta. There has been no external security audit, only an internal review. The cryptography itself is not ours: Olm and Megolm (as in Matrix/Element) via the open-source vodozemac and matrix-sdk-crypto libraries.

What is encrypted

• Only direct messages and groups where end-to-end encryption is switched on. Server (community) channels are never encrypted.
• Any member can switch it on in the chat details (a group owner may keep that right to themselves). It cannot be switched off. Text, edits and files (including names and previews) are encrypted.
• For now new DMs are not encrypted automatically; this becomes the default later. Groups stay manual.
• Encryption is available in the Android app. The Windows app gets it later and until then shows “Encrypted message. Update the app.”

What the server sees

The server cannot read encrypted messages or files; plain text and private keys never leave your devices. It does see metadata: who talks to whom, when and how much, message sizes, reactions, replies, pins, group members, system messages, the number and sizes of files, your devices and their public keys. Calls and video are not end-to-end encrypted.

Devices and emoji verification

Every login is a device (Settings → Devices and encryption). “Verify” shows 7 emoji on both screens: compare them in person or over a call. Verify your contacts and your own devices — only a verified own device hands your old message keys to a new one.

Recovery key and key backup

Your message keys can be backed up on the server, encrypted with your recovery key; the server cannot read the backup. The key is shown once. A lost recovery key cannot be recovered by anyone, not even the administrator.

Key files

“Export keys” saves keys to a file protected by a passphrase. The passphrase cannot be recovered, and the file plus the passphrase reads every chat it contains — keep both safe and never share them.

Limits

• No message search (pins work), no link previews, no server-side file previews.
• Calls are not end-to-end encrypted. No bots or webhooks in encrypted groups.
• Push notifications carry no text: the phone decrypts on its own, otherwise it shows “New message from …”.
• New group members do not see older messages; a new device does not see them until verified or restored.

What to do

• New phone: keep the old one logged in, log in on the new one and verify it with the old one or restore with the recovery key. Without both, old encrypted messages are lost; new ones work.
• Lost phone: from another device (or the new phone) open Devices and encryption and log the lost one out, change your password, restore history with the recovery key.
• “Update the app”: install the latest Android version. If the app says its encryption data was saved by a newer version, update — do not reset encryption.

Diagnostic report

Devices and encryption → Diagnostics → Send diagnostic report: counters, states and error codes, app and Android versions, CPU type and number of accounts. No messages, keys, server address or other people’s IDs. You see the whole report before you choose where to send it.