"as defined by whom? Some government (which one) organization ?"
As defined by the user.
RA doesn't care what software you run. In fact RA is better supported by Linux than any other OS! And, although the discussion in this thread is about RA of entire machines, that's actually pretty old school. Modern RA is all about attesting the tiniest slice of code possible, hence the "enclave" terminology. The surrounding OS and infrastructure doesn't get attested because it can be blinded with encryption. This is beneficial for both sides. I don't actually necessarily care how you configure your OS or even if it's up to date with security patches, if the security model treats the entire OS as an adversary, which is how Intel SGX works. You just attest the code inside the enclave and I send/receive encrypted messages with it.
As defined by the user.
RA doesn't care what software you run. In fact RA is better supported by Linux than any other OS! And, although the discussion in this thread is about RA of entire machines, that's actually pretty old school. Modern RA is all about attesting the tiniest slice of code possible, hence the "enclave" terminology. The surrounding OS and infrastructure doesn't get attested because it can be blinded with encryption. This is beneficial for both sides. I don't actually necessarily care how you configure your OS or even if it's up to date with security patches, if the security model treats the entire OS as an adversary, which is how Intel SGX works. You just attest the code inside the enclave and I send/receive encrypted messages with it.