Labyrinth 1.1 solves a critical availability challenge in E2EE systems by ensuring message persistence even when devices are offline. This improves reliability and user experience in secure messaging without compromising the privacy guarantees of end-to-end encryption.
Good security should always be invisible. When Meta launched encrypted backups for Messenger in 2023, we set a new bar for end-to-end encrypted (E2EE) messaging at scale. With E2EE messaging backups your message history can travel with you across devices without ever being readable by any other party, including Meta.
Today, we’re evolving the work we began with Labyrinth, our protocol for end-to-end encrypting stored messages history between devices on your Messenger account. Labyrinth 1.1 improves backup reliability with a new sub-protocol that lets messages reach your encrypted backup as they’re sent, rather than waiting for your device to come back online, which is how Messenger encrypted backups currently work.
This means your messages are safe even if you lose your phone, switch devices, or have a long gap between sign-ins. Each message is wrapped with a message encryption key that the sender places directly into the recipient’s encrypted backup — like dropping a sealed envelope into a locked box only the recipient can open. No one but you and the people you’re talking to can read your messages – not even us.
We’re rolling Labyrinth 1.1 out broadly to Messenger and are already seeing meaningful gains with more messages successfully backed up and more people restoring their full message history when they change devices.
Read our updated white paper, “The Labyrinth Encrypted Message Storage Protocol” for more information.
The post Labyrinth 1.1: Making End-to-End Encrypted Backups Even More Reliable appeared first on Engineering at Meta.
Continue reading on the original blog to support the author
Read full articleWhatsApp's migration demonstrates that Rust is production-ready for massive-scale, cross-platform applications. It proves memory-safe languages can replace legacy C++ to eliminate vulnerabilities while improving performance and maintainability.
Sapienz demonstrates how academic research in multi-objective automated testing can scale to industrial production. It improves reliability by finding and simplifying crash reproduction at scale, while evolving toward LLM-driven autonomous agents for functional correctness.
MoQ unifies fragmented media protocols into a single QUIC-based standard. It reduces architectural complexity while providing lower latency and better resilience for real-time applications at global scale, enabling a consistent foundation for future interactive and AI-driven experiences.
Time is the foundation of security decisions like certificate validation and token expiry. As certificate lifespans shrink, secure time via NTS becomes essential to prevent automated renewal failures and man-in-the-middle attacks on foundational internet protocols.
