Recently cult of the dead cow came out with veilid, a secure decentralised way of sending encrypted information and i think this could be a huge asset to lemmy. Cult of the dead cow even mentions mastadon by name as they say this is the type of application it was designed for. If veilidchat takes off then i really hope the devs will consider it.
Consider opening a feature request ticket on Github. :) or better yet, start working on it if you’re able to.