BeeKEM: A Novel Key Encapsulation Mechanism for Decentralized Secure Group Messaging
2025-06-19
This article delves into BeeKEM, a novel key encapsulation mechanism for decentralized secure group messaging. Unlike traditional TreeKEM, BeeKEM enhances recovery from conflicting offline updates and network splits by allowing multiple group state "epochs" to coexist simultaneously. When members receive conflicting updates, they retain all received keys, marking them as "conflicted," thus continuing to decrypt and read messages from conflicting epochs. Updates proceed by treating conflicted nodes as blank. BeeKEM unlocks new possibilities for building local-first apps with stronger privacy and autonomy.