Gematik co-funded the most recent Matrix audit of vodozemac[1], and is poised to fund 3 more (of matrix-rust-sdk-crypto, matrix-rust-sdk and the whole stack end-to-end) to ensure the E2EE is where it needs to be. So I'd say that the German government definitely cares about E2EE for its civil servants, and we're very grateful for them funding security research.
Meanwhile, BWI is helping fund the work needed to address clientside controlled room membership (https://github.com/matrix-org/matrix-spec-proposals/pull/391...) as highlighted in your paper, as well as TOFU... and they're also funding work to provide MLS as an option for E2EE in Matrix too[2].
Unsure why you're talking about the unexploitable IND-CCA break :)
Meanwhile, BWI is helping fund the work needed to address clientside controlled room membership (https://github.com/matrix-org/matrix-spec-proposals/pull/391...) as highlighted in your paper, as well as TOFU... and they're also funding work to provide MLS as an option for E2EE in Matrix too[2].
Unsure why you're talking about the unexploitable IND-CCA break :)
[1] https://matrix.org/blog/2022/05/16/independent-public-audit-...
[2] https://www.golem.de/news/bwmessenger-vom-messenger-der-bund...