{"guid":"cbb49d37-51b0-5388-bff0-3ec9dd8933c6","title":"Beyond Olm","subtitle":"About challenges and opportunities in Messaging Layer Security (MLS)","slug":"matrix-conf-2025-71182-beyond-olm-about-challenges-and-opportunities-in-messaging-layer-security-mls","link":"https://cfp.2025.matrix.org/matrix-conf-2025/talk/BAKSEA/","description":"[matrix] as an end-to-end encrypted communication standard has its flaws. Flaws in privacy, flaws in complexity. With the standard of Messaging Layer Security (MLS), the [matrix] ecosystem has the opportunity to address old flaws, rethink room state and increase interoperability.\r\n\r\nIn this talk, I will provide a beginner's guide on challenges of [matrix] 3.0.\r\n\r\n\u003e Messaging Layer Security (RFC 9420, MLS) is a modern layer for end-to-end encrypted group messaging providing Forward Secrecy (PFS) and Post-Compromise Security (PCS). MLS further provides performance that’s logarithmic in the group size, an easy migration to post-quantum security, and is a rigorously analyzed protocol.\r\n\r\nThis talk will discuss the opportunities and challenges offered by MSC4256 proposing a way to integrate MLS into [matrix] rooms.\r\n\r\nAs a guidance, I will focus on the following questions :\r\n\r\n- Which advantages does MLS feature over Olm ?\r\n- Which tradeoffs can we accept with an interoperable encryption standard ?\r\n- How can we keep a federated ecosystem working with an encryption standard not meant for complete distribution ?\r\n- How can we ensure to keep sync of MLS state and [matrix] room state ?\r\n- How can we incrementally migrate an ecosystem to another encryption standard ?\r\n\r\nThe entire topic of MLS is obviously too big for a single talk. Many of the open questions may only be discussed briefly. The aim of this talk is not to present outstanding solutions like a miracle but rather to inform about the current state of the specification, the ecosystem and next steps.\r\n\r\nLicensed to the public under https://creativecommons.org/licenses/by-sa/4.0/","original_language":"eng","persons":["The one with the braid (she/her)"],"tags":["71182","2025","matrix-conf-2025","Security \u0026 Encryption","Lynn Conway","matrix-conf-2025-eng","matrix-conf-2025","Day 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