Online / 5 & 6 February 2022


Self-sovereign end-to-end encrypted file storage on Matrix

How we built a file system on top of Matrix

Matrix is an open source project run by the non-profit Foundation dedicated to building an open protocol and communication network for decentralised, encrypted communication - providing a viable open alternative to WhatsApp, Slack, Discord and other proprietary communication silos.

During 2021 we have been exploring how the Matrix protocol can be used for decentralised, end-to-end encrypted online document storage and collaboration as an alternative to centralised proprietary services such as Dropbox and Box. In this talk we will show off our progress so far and the further work that we have planned.

Matrix is essentially a generic mechanism for replicating structured data over a decentralised network of untrusted servers. The first use cases of Matrix have focused on instant messaging and VoIP, but during 2021 we’ve been experimenting with replicating different types of structured data - such as MSC3089 (, which models each Matrix room as a directory, which can contain subdirectories by acting as a Matrix Space, which in turn can contain files as normal Matrix file uploads described by appropriate state events. We’ve also been looking at further expressing the file data as structured trees of Matrix events.

Meanwhile, the need for self-sovereign file-storage and collaboration systems is growing ever more obvious, given the risks of trusting your data unilaterally to a proprietary and typically unencrypted 3rd party cloud service. However, there is currently a trade off between the typical productivity gains from non-privacy centric online collaboration versus the more limited pro-privacy solutions currently available.

Can Matrix support the next generation of privacy-centric collaboration applications? Providing document and file storage capabilities is one of the areas we’re looking at.

Topics that we will cover: * File and folder semantics * Version history * Sharing and access control * Document editing * Use cases: demos * Matrix protocol specification work to standardise approach and support interoperability * Files SDK for JavaScript to make it easy to get started * Next steps


Photo of Hugh Nimmo-Smith Hugh Nimmo-Smith