There is a rumor that Ryzen Pro will employ an ARM co-processor (Coretex A5) to enable SME (Secure Memory Encryption) and SEV (Secure Encrypted Virtualization) on DDR memory.
That thing is called Platform Security Processor. It has been a thing for a while, since its first appearance in the Bemma APU. Basically it is trusted root + secure bootchain + crypto engine, and SME/SEV (announced a few months ago as a whitepaper) works on top of it.