I don't see how the RDRAND change would be gotten away with either, if someone else is looking at the silicon design. To modify RDRAND so that it is less rando

I don't see how the RDRAND change would be gotten away with either, if someone else is looking at the silicon design. To modify RDRAND so that it is less random in a way that's useful for an attacker, yet passes statistical randomness testing by the OS and other software, would require RDRAND to implement something cryptographic, so that only the attacker, knowing a secret, can "undo" the not-really-randomness. A new crypto block would surely be very noticable at the RTL level.