X-ray won't catch substitute chips: they will have the same package and same markings but a few extra functions on their silicon. Good luck eyeballing that one.

X-ray won't catch substitute chips: they will have the same package and same markings but a few extra functions on their silicon. Good luck eyeballing that one. I think you're right though: they should examine a sample of the boards at lest. In addition--layering defense--one would imagine simply putting a motherboard on a quarantine LAN, simulating their production network, and watching its network traffic for phoning home. The real implants might be waiting for a specific situation, like a date or a string on the bus, so you never really know if you got them all.