Project Hydra (phase 2+3): further improving the security of the federation protocol
The federation protocol is how Matrix homeservers communicate between each other. In private federations this isn't particularly challenging as the network is trusted but in the public federation this isn't true. This talk dives into what protocol improvements are in the works to make the public federation more secure against Byzantine actors, particularly against "backdating": intentional misuse of the concurrency primitives to manipulate the authorisation algorithm. We'll explore why this problem is hard, what some of the failure modes are, and how we are working on addressing them.
Some of this work was presented in a peer-reviewed article.
Kegan Dougal is one of the core engineers who created Matrix back in 2014, designing many aspects of the client-server protocol.
He has extensive experience with most of the Matrix ecosystem including servers (Synapse/Dendrite), clients (Element-Web/JS SDK), bots (Go-NEB) and bridges (IRC bridge). He has written several test frameworks from Complement to Chaos, ensuring the entire ecosystem remains interoperable, robust and reliable. His current focus is on improving the federation protocol and is collaborating with academia in the CRDT field to ensure Matrix remains secure against Byzantine actors.