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Security

Your chats, explained plainly

What stays between you, what the server sees and what you can add yourself. No overblown promises.

  • Locked on your phone

    Private chats and calls are locked on your phone and only open on the phone of the person receiving them.

  • The server delivers

    It gets messages where they need to go, but it doesn’t have the key to open them. It knows who writes to whom and when, because it needs to.

  • You decide

    With a number or without, with app lock, locked chats and two-step verification.

A message’s journey

From your phone to the one receiving it

  1. You write

    The message is born on your phone, in plain text, just for you.

  2. The app locks it

    With the recipient’s public key: from here on, only their key can unlock it.

  3. The server delivers it

    It receives a block of meaningless letters, plus what it needs to deliver it.

  4. It unlocks

    On the recipient’s phone, with their private key, which never leaves the phone unprotected.

What’s protected

Not everything works the same way

Knowing where you’re writing helps you choose what to share.

Stays between you

  • Private chats between two people, with photos, files and voice notes
  • Groups without visible history
  • Voice and video calls
  • Secret messages

Works differently

  • Groups and channels with visible history: messages stay readable on the server and, if the space is public, they can show up in Discover
  • Profiles, profile photos and stickers: whoever opens them can see them
  • The chat with Hidesay AI: to answer you it has to be able to read it, so it isn’t private like the ones between two people
  • Bots without a key: they read in plain text through the server, and the app tells you beforehand
  • Who writes to whom and when: the server knows, it needs that to deliver

Keys

The app makes the key, you don’t have to think about it

  • Created on its own

    The first time you sign in, the app creates the key for your messages and protects it on your phone.

  • A copy for your new phone

    The app can keep a protected copy of your key on the server, to bring it to another phone. You can turn it off and export the key to keep it yourself.

  • A code to check

    Every contact has a security code. If you want to be sure, compare it in person or over another channel you trust.

Your protections

The ones you can add yourself

  • App lock with a PIN or fingerprint
  • Locked chats, with no preview in the list or in notifications
  • Two-step verification
  • Message previews hidden in notifications
  • Linked devices to check and sign out
  • Last seen and online status hidden, if you want

For those who want the details

The technology behind it

You don’t need the names below to use the app. We list them for those who want to check.

Open source code
The app’s code is public: anyone can verify how it locks, unlocks and signs messages.
OpenPGP
The open standard used to lock the messages of protected chats and their attachments, from one phone to the other (end-to-end).
Ed25519 and RSA
The key types the app can create.
Calls
Every audio and video packet is an OpenPGP message of its own.
Android Keystore
Protects the private key and the app’s data on the phone.
Notifications
Only a signal to wake the app goes through Firebase: the phone downloads and opens the message itself.
AES-256-GCM
Locks the content of groups and channels with visible history on the server.
Argon2id
The server only stores an Argon2id hash of sign-in credentials, never the credentials in plain text.

Keep in mind

The limits, stated clearly

  1. Anyone using your unlocked phone sees what you see. App lock helps, but it doesn’t delete copies or screenshots others have already saved.
  2. If you turn off the key copy and lose your phone, messages protected with that key can’t be opened again. Getting back into your account isn’t enough.
  3. Resetting your PIN or password requires a verification and a waiting period, and it deletes the old copies of your key.
  4. The 16 digits of an account without a number can’t be recovered if you lose them: nobody, not even us, can verify that the account is yours.

Reports

Found a security issue?

Tell us what you found and how to reproduce it. Never send us PINs, passwords or your account’s 16 digits.

[email protected]

If you use PGP you can encrypt your report with our public key, and attach yours if you want an encrypted reply.

Key fingerprint

C560 B866 DB50 24AE 58AC 69C7 BA54 4307 77C0 72BD
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