Your devices

Conversations in Tacq are encrypted so that only the devices you have added to your account can read them. Not the account in general — the devices: your phone, a second phone, a browser on your computer. That is why entering your Master ID and password on a new device is not enough: the device has to be linked.

Main device and linked devices

The main device is the one you created the account on. It decides who else belongs to your circle: it links new devices and unlinks old ones.

A linked device is one the main device has admitted. It reads and writes just like the main one, but it adds nobody itself.

There is always exactly one main device. If you bring your access back with the recovery phrase on another device, that device becomes the main one.

How to add a second device

You need both devices side by side, and you must already be signed in on the new one.

1. On the new device: Settings → Link a device → “This is a new device”. It will show a code.
2. On the main device: Settings → Link a device → “This is my main device”, and scan the code. If there is no camera, the code can be typed in by hand.
3. The same six digits appear on both screens. Compare them with your own eyes. If the digits differ, stop: someone else is on the other end.
4. Done. If you choose so, the most recent part of your conversations moves to the new device as well — directly, bypassing our server.

“This device is not linked”

This is the app saying that you have signed in, but the device has not been added to the account yet. You can send messages from here; nothing will arrive here.

There is one way out — link it from your main device, as described above. If you no longer have your main device, the recovery phrase is what helps: see If you lose your phone.

What happens when you sign out

Signing out is not “stepping away for a minute”. It takes everything off the device:

• the conversations stored here are erased;
• the keys are erased too, and the device stops being linked.

After you sign in again, this device has to be linked anew. This is deliberate: if somebody else sits down at that computer and signs into their own account, your conversations must not come along.

Clearing the site data in a browser does exactly the same. For the app it is indistinguishable from signing out: you will see the sign-in screen again, and after signing in — “this device is not linked”.

Unlinking a device

Settings → My devices lists all your devices. Only the main device can unlink.

An unlinked device immediately loses access to new conversations: the key that encrypts your personal data changes, and the new one no longer reaches it. Whatever had already been saved on that device stays there — we cannot reach into somebody else’s device and take it back, so unlinking is no substitute for care.

A device you signed out from may stay in the list — it reads nothing, but it takes up a line. Such an entry can be unlinked by hand.

If you have several devices

• Messages arrive on every linked device.
• The mark showing unread messages in a session is separate on each device. It goes out when you open that session on that device.
• The recovery phrase is created on the main device only.