Messages encrypts all conversations. You need a security key to access your messages on multiple devices or after signing out.
- Click your profile picture in the top left.
- Select Security and privacy [VERIFY].
- Click Set up secure backup [VERIFY] under Encryption.
- Choose Generate a security key and download or copy the key.
- Store the key somewhere outside this device, for example in a password manager.
You will need the key the next time you sign in on a new device or browser.
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