Some of these features makes it harder to (physically) probe the internal parts of the chip and read out secret values: https://en.wikipedia.org/wiki/Secure_cr

Some of these features makes it harder to (physically) probe the internal parts of the chip and read out secret values: https://en.wikipedia.org/wiki/Secure_cryptoprocessor#Features https://en.wikipedia.org/wiki/Secure_cryptoprocessor#Feature... These things make it harder to break into the internals of the chip regardless of they being kept secret, so I wouldn't call it security by obscurity. I'm not even sure you can apply that principle to physical security.