[616c]

I wish RCS could somehow be merged with IETF MLS specs but I know that is apples and oranges and not so possible.

The RCS proprietary encryption bit is very sad. Oh well.

[FactolSarin]

Google's RCS encryption scheme isn't really proprietary, it's the Signal e2ee scheme. Granted, it's bolted into RCS and not part of the standard, but it's not 100% closed either. It's like a standard added to another standard in a nonstandard way.

[kelnos]

The key management is proprietary, for some reason. Can't build an interoperable impl without that.

[jvolkman]

Google already announced that Messages will support MLS. One can only hope that Apple does as well with whatever this announcement brings, and that MLS becomes the defacto E2EE standard for RCS.