Using Ptychographic X-ray laminography to detect hardware backdoors

Detecting backdoors in hardware is hard. I just noticed this paper from last year:

X-Ray Tech Lays Chip Secrets Bare: Researchers in Switzerland and the U.S. have a non-destructive technique that can reverse engineer an entire chip without damaging it[…]

https://spectrum.ieee.org/nanoclast/semiconductors/design/xray-tech-lays-chip-secrets-bare

https://zenodo.org/record/2657340

https://www.nature.com/articles/s41928-019-0309-z

https://en.wikipedia.org/wiki/Hardware_backdoor