"The crucial chips could be built under "open inspection" conditions, much like having source code for inspection prior to compilation on one's own--presumably trustworthy--machines. Several such vendors could be used, with independent auditors observing the processing steps throughout. (Merely the threat of a surprise inspection is probably enough to head off obvious attempts to insert hardware trapdoors and the like.) This seems like a solvable problem." It seems to me that an ostensibly digital device with a fixed number of pins could be regarded as a finite state system, and systematically analyzed accordingly, IE, traverse the set of possible combinations of pins and signal levels and verify that it behaves in accord with pub- -lically available specifications. I'm no circuit designer ( yet ), but it seems to me that the microchip might be subject to design to make it conform to such tests, yet still contain additional circuitry which is undocumented. It might also have analog circuitry, I suppose, although I cannot immediately conceive of a use for such a thing. ( Of course, nanotech rears its ugly head, but that sword cuts both ways and, until it manifests, is irrelevant. ) Perhaps a chip could be tested, at the cost of additional time, by a systematic profiling of the finite boundaries of the device as repre- -sented by the combination of pins being stimulated, the combination of pin input voltage levels, and the resulting pin output voltages. If you want to be fanatical, you can also profile the resulting fields. It seems to me that it would be difficult to defy such a systematic profiling. ( I guess one could also test the I:E:R ratios at each of the states to further detect bogus circuitry, as well as borderline products. ) Why quality assurance lines don't do this on a chip-by-chip level now is beyond me. I'll bet the Japanese do now, or are working on it ... -- richard ===== -- richard childers rchilder@us.oracle.com 1 415 506 2411 oracle data center -- unix systems & network administration Klein flask for rent. Inquire within.