Steven M. Bellovin wrote: > Does that mean that the new fiber is less tappable?
No change, notwithstanding anecdotal references on fiber bending as used for tapping. Tapping a fiber can be done without much notice by matching the index of refraction outside the outer fiber layer, after abrasion and etching to reach that layer. There is no need for bending, which might not be physically possible (eg, in a thick cable bundle), would increase propagation losses beyond that caused by the tapped signal power itself, and might create detectable backward propagating waves (BPWs are monitored to detect fiber breach). Low-loss taps are essential. A tap must extract a portion of the through-signal. This, however, should not have the effect of significantly reducing the level of the remaining signal. For example, if one-quarter of the incident signal is extracted, then there is a 1.25 db loss in the remaining through-signal, which can easily be detected. Cheers, Ed Gerck --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
