[cap-talk] impossibility of solving the "coordinated attack problem" ("generals problem")

[David Wagner]

Ian G <iang at systemics.com> writes:
>I would say that the usefulness of the result is to show that there are
>no reliable channels.  Full stop.

Nope, that's wrong.  The argument says that *if* you use an unreliable
channel, then such-and-such can happen.  Note the difference between
a premise and a conclusion.  The question of whether reliable channels
exist or not is a question of physics, not of algorithms, and this proof
does not purport to show that reliable channels cannot exist.