> I think that would require E being in the middle in all phases of interaction between A and B, from connection initiation. Yes, that's right :-) Keep in min

> I think that would require E being in the middle in all phases of interaction between A and B, from connection initiation. Yes, that's right :-) Keep in mind, though, that in practice it may be possible to force re-initiation -- e.g., by feigning timeout, by feigning loss/corruption on the received data, etc.