Interesting about how some of the trojan chips were hidden in PCB substrate layers to avoid optical detection. For a much stealthier approach again, it was show

Interesting about how some of the trojan chips were hidden in PCB substrate layers to avoid optical detection. For a much stealthier approach again, it was shown in 2013 that slighting changing the dopant mask for a few gates on Intel Ivy Bridge chips could render RNGs insecure[1][2]. Mask inspection systems[3] are used to detect mask manufacturing defects, but the question then is, do those inspection systems use Super Micro motherboards? [1] Paper: http://www.emsec.rub.de/media/crypto/veroeffentlichungen/2015/03/19/beckerStealthyExtended.pdf http://www.emsec.rub.de/media/crypto/veroeffentlichungen/201... [2] Presentation: https://www.iacr.org/workshops/ches/ches2013/presentations/CHES2013_Session4_3.pdf https://www.iacr.org/workshops/ches/ches2013/presentations/C... [3] Example system: https://www.lasertec.co.jp/en/products/semiconductor/mask_semicon/matrics_x8ultra.html https://www.lasertec.co.jp/en/products/semiconductor/mask_se...