3 ms·
I would guess that at the lowest level too much is dictated by physics. It may be possible to obfuscate some higher abstraction layers though.
by comboy 7y ago
I would guess that at the lowest level too much is dictated by physics. It may be possible to obfuscate some higher abstraction layers though.
- kaibee 7y agoI wouldn't be too sure of that. > Five individual logic cells were functionally disconnected from the rest— with no pathways that would allow them to influence the output— yet when the researcher disabled any one of them the chip lost its ability to discriminate the tones. Furthermore, the final program did not work reliably when it was loaded onto other FPGAs of the same type. https://www.damninteresting.com/on-the-origin-of-circuits/ https://www.damninteresting.com/on-the-origin-of-circuits/
- sephamorr 7y agoNote the last sentence of your quote. Device-to-device variability and production yield are opposites. I can't imagine how techniques that exploit variability between devices (with no mention of temperature, lifetime drift, etc) could be reliable.
- labawi 7y agoMaybe not the best example, but this was on FPGA. When making custom chips, you can make all sorts of tuning, including consistent hardly noticeable drifts from spec. The article says they only image the metal layers, so I guess you can do anything as long as you don't visibly change the metal layers.