@david_chisnall@infosec.exchange
Post #4201641
2026-07-29 14:34 UTC
@crazyeddie@mastodon.social @mario@don.tbully.me
In certified software development--the ones I was involved with and read about anyway--this is done by a person who signs off that the implementation follows the spec correctly.
No it isn't. At no point in certified software development will anyone sign of on (for example) the C compiler's output being a 100% faithful representation of the C abstract machine. At least, not in any situation where liability may lead back to them, because it is never true (well, it's technically true for CompCERT, though with the all-bets-are-off-if-your-source-code-has-any-undefined-behaviour get-out-of-jail-free card).
Described situation was a demo during research phase sounds like. I hope they'd have found this before it made to production but yeah, no guarantees.
No, the point of the demo was that you would not find this. It was a tweak that was possible to make during back-end layout or to the GDSII after you've sent it to the fab, so a completely plausible supply-chain attack on a hardware security mechanism.
This kind of attack is easier on hardware than software, because you can at least run a compiled program on a simulator.
Replies (1)
-
@crazyeddie@mastodon.social 2026-07-29 14:35
@david_chisnall@infosec.exchange @mario@don.tbully.me "At no point in certified software development will anyone sign of on (for example) the C compiler's output being a 100% faithful representation of the C abstract machine." This is quite the straw man you've summoned. Didn't get any better either. Later.