Yes. I wasn't intending to suggest an attack based solely on masks.
Yes - it'd never work. Electronic Engineers are a strange bunch. I've spent way too much of my time in a room full of people staring at mask plots of various 50M transistor and up CPUS looking for flaws, areas for optimization, etc. It's part of every CPU design cycle and the developers hate it, but it has to be done. If the mask doesn't match the circuit you designed, you can spot that kind of thing fairly quickly. If it didn't match in a way that actually did something useful, then it'd leap right out at you as soon as you unfurled the plot. It's not just at the design review stage, either. The fab people are constantly processing the chip design, performing their own reviews, staring through microscopes at the wafers: working on alignment issues, probing test points, stripping layers and taking cross-sections to examine everything from VIA quality to metalization issues. Something out of the ordinary would make itself obvious pretty quickly. These people live inside their chips. That's why they sort of work. Regards, Robert. --=20 Robert Walsh Amalgamated Durables, Inc. - "We don't make the things you buy." Email: rjwalsh@durables.org -----------------------------------------------------------