As a former chip designer I question the idea that the manufacturer introduced this backdoor (if indeed there is one). found a previously unknown backdoor inse

As a former chip designer I question the idea that the manufacturer introduced this backdoor (if indeed there is one). found a previously unknown backdoor inserted by the manufacturer. This backdoor has a key... It's hard to understand what this guy is talking about. Is he claiming that the manufacturer added additional hardware that the designers were unaware of? Or they made modifications to existing circuitry so it doesn't match the design? It would be very hard to do either without cooperation from the designers, especially given the paranoia of hardware engineers (and of defense hardware engineers, an entirely different level of paranoia). The question "are we manufacturing what we designed?" is one that is constantly asked throughout the lifetime of a part. In fact the answer, for individual parts, is often "no", because they can be defective. Still, the question is constantly asked with a variety of automated tools at all points of the manufacturing process. Here's what I think he might have found: an additional fixed key introduced by the designers themselves into the chip, and having nothing special to do with the manufacturer. In other words, a deliberate backdoor.