Accumulating a list of resources that might be helpful in solving this problem. Feel free to respond with more materials. I will also try to keep the main post updated so that it contains all links from the thread:
FMD:
- Original paper on e-print
- Penumbra Sender and Receiver FMD
- Another FMD paper that might be interesting
From zcash:
- Private Money <> Private Messaging
- DAGSync: wallet optimization for scanning the relevant transactions first
Other approaches:
TEE:
TEE blockchain clients:
Misc: