Labyrinth 1.1: Making End-to-End Encrypted Backups Even More Reliable

Meta is rolling out Labyrinth 1.1, an updated version of its end-to-end encrypted backup protocol for Messenger. The key improvement is a new sub-protocol that allows messages to be backed up as they are sent, rather than requiring the recipient's device to be online. Each message is wrapped with a message encryption key placed directly into the recipient's encrypted backup, ensuring message history survives device loss, device switches, or long gaps between sign-ins. Meta reports meaningful gains in backup success rates and full history restoration during device changes.