You can't trust any computation on hardware that cannot be trusted. There is no way to check that. Any software implemented check to detect that can be thwarted

You can't trust any computation on hardware that cannot be trusted. There is no way to check that. Any software implemented check to detect that can be thwarted by hardware that misbehaves in malicious ways. Imagine an address based instruction replacement table that is used to convert some key consitional branches into unconditional ones.