Labyrinth 1.1: Making End-to-End Encrypted Backups Even More Reliable (opens in new tab)
Meta is rolling out Labyrinth 1.1, an updated encrypted storage protocol for Messenger. Its main improvement is more reliable end-to-end encrypted backups: messages can be backed up as they are sent, even when the recipient’s device is offline. This helps preserve message history after device loss, replacement, or long periods without signing in, while keeping messages unreadable to Meta and other parties. ## Labyrinth 1.1’s Backup Improvements - The new sub-protocol sends messages to the recipient’s encrypted backup immediately rather than waiting for their device to reconnect. - This addresses limitations in Messenger’s current encrypted backup process. - Backups remain protected by end-to-end encryption, so only the users involved in the conversation can access the message contents. ## How Message Encryption Works - Each message is wrapped with a message encryption key. - The sender places that key directly into the recipient’s encrypted backup. - The design is compared to putting a sealed envelope into a locked box that only the recipient can open. - Meta cannot read the stored messages or their encryption keys. ## Rollout and Results - Labyrinth 1.1 is being broadly rolled out across Messenger. - Meta reports that more messages are being backed up successfully. - More users are also restoring their complete message history when switching devices. The updated “Labyrinth Encrypted Message Storage Protocol” white paper provides the detailed technical specification.