Ed Gerck <[EMAIL PROTECTED]> writes: > Perry E. Metzger wrote: >> Ed Gerck <[EMAIL PROTECTED]> writes: >>> Each chip does not have to be 100% independent, and does not have to >>> be used 100% of the time. >>> >>> Assuming a random selection of both outputs and chips for testing, and >>> a finite set of possible outputs, it is possible to calculate what >>> sampling ratio would provide an adequate confidence level -- a good >>> guess is 5% sampling. >> >> Not likely. >> >> Sampling will not work. Sampling theory assumes statistical >> independence and that the events that you're looking for are randomly >> distributed. > > Provided you have access to enough chip diversity so as to build a > correction channel with sufficient capacity, Shannon's Tenth Theorem > assures you that it is possible to reduce the effect of bad chips on > the output to an error rate /as close to zero/ as you desire. There is > no lower, limiting value but zero.

No. It really does not. Shannon's tenth theorem is about correcting lossy channels with statistically random noise. This is about making sure something bad doesn't happen to your computer like having someone transmit blocks of your hard drive out on the network. I assure you that Shannon's theorem doesn't speak about that possibility. The two are not really related. It would be wonderful if they were, but they aren't. Indeed, Shannon's tenth theorem doesn't even hold for error correction if the noise on the channel is produced by an adversary rather than being random. I'm not particularly inclined to argue this at length. Perry --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]