Encryption protects you — but only if you protect your keys.
When you create your account, you receive an encryption recovery key. It's a long, unique string that unlocks your encrypted message history when logging in on new devices. It looks something like this:
↑ Example only. Yours will be different.
End-to-end encryption means your messages are not readable by the server — not by us, not by anyone. The recovery key is the only way to access your encrypted history on a new device. If it's gone, the history is gone.
You can still use your account and send new messages. However: