Can you not use the one not known to intel to do your own code signing against another client with ECDH? Why does it seem like they are pushing this "Intel Attestation" service? Wouldn't that cause Intel servers to be a single POF incase they aren't around to give a proper reply for the attestation request? (Imagine 100,000 nodes on the network all running smart contracts, or perhaps 10 years down the line they discontinue the service.)