How privacy works.
A plain account of what happens to a message after you press send, and what we can and can't see along the way.
Sealed on your device. Opened on theirs.
Messages, calls, photos and files are encrypted before they leave your device. Our servers pass them along and store them, but can't open them.
Your device
"Dinner on Friday?"
Polymorph servers
9f1c 07ab e2d4 5c18 b9e0 4a7f 31dd 0c6e …
Stored and delivered. Not readable.
Their devices
"Dinner on Friday?"
Every device holds its own keys.
Your phone, your laptop and your desktop each have keys of their own, created on the device. They never leave it, and we never have a copy.
To add a device, you approve it from one you're already signed in on, or sign in on it with your user key and secret key. Remove a device and it no longer receives anything new.
When you sign up, you get a user key and a secret key. They're shown once. Keep them somewhere safe: we can't recover an account for you, because we never hold your secret key.
iPhone
Added 3 March
Own keys
MacBook
Added 4 March
Own keys
Desktop
Added 9 June
Own keys
To deliver a message, a server has to know where it goes. That's about all.
Our servers can see
- Your handle, your plan and how much storage you use
- Which devices belong to your account: each as a random ID with its platform (such as Android), not its name or model
- Who is in a group or Space, and their role
- When something is sent, and roughly how large it is
- Network details such as IP addresses and connection times
Seeing isn't keeping. What we store, and for how long, is set by our retention rules, not by what passes through the servers. See how long we keep data.
Our servers can't see
- What you write, and the photos, voice messages and files you send
- What's said or shown in calls, group calls included
- What's in your events, polls, lists, notes and expenses
- What's in a Space's channels, task boards, logs, inventories and files
- Your keys and your secret key
Notifications reach your phone through Apple's and Google's push services, which see that your device was sent one. Group calls, and calls that can't connect directly, pass through our servers. They stay encrypted on the way.
An account that isn't tied to a SIM card.
You sign up with a handle. We don't ask for a phone number or an email address.
Handles are public, so anyone who knows yours can send a contact request. You decide who becomes a contact, and you can change your handle once a month.
Built on an open standard, so it can be checked.
Chats and groups use Messaging Layer Security (MLS), an open standard published by the IETF and designed for groups of any size. We use an open-source implementation rather than a scheme of our own.
What encryption doesn't cover.
Encryption protects your messages on the way and on our servers. It can't protect an unlocked device in someone else's hands, or stop a person in the chat from taking a screenshot or forwarding what you sent.
A screen lock on your devices, and some care over who you add, still matter.