After the first beta was iPhone to iPhone only, the second iOS 26.4 developer beta lets iPhones and Androids trade fully encrypted RCS messages for the first time.
RCS support will be extended to include end-to-end encryption
RCS support will be extended to include end-to-end encryption
You may recall that in the first iOS 26.4 developer beta, Apple introduced end-to-end encryption (E2EE) for RCS messaging. You may also remember that it was extremely limited and only worked between iPhones with iMessage disabled.