Reminds me of a general-purpose version of the secure enclave that Moxie Marlinspike blogged about when he implemented secure contact look-up in Signal. Very cool Google released this as open source. Of course, it does require you to be able to trust the security of the enclaves and (at least in the Signal implementation) requires you to make some different performance trade-offs in order to prevent information leakage.
Tangent: On a whim I Googled 'secure enclave risc-v' and, sure enough, there's an extension in development called "Keystone."[0] RISC-V really has such a promising future.