Support for FHE and SMPC

Are there any plans or support for the following?

- Full Homomorphic Encryption (FHE)
- Secure Multi Party Computing (SMPC)

There seemed to have been some effort on FHE in the past, but unsuccessful:
[SEAL Homomorphic Encryption support](https://github.com/dotnet/machinelearning/pull/4407)
[WIP: Homomorphic encryption](https://github.com/dotnet/machinelearning/pull/4229)

With the above becoming popular in other ML frameworks (PySyft, Azure Encrypted Inference, XayNet, etc), it would be good to look into the above areas again. There doesn't seem to be anything similar for .Net (C# or F# for that matter).