[comp.dcom.telecom] Callback Security via Call-Forwarding

elmo@bu-it.BU.EDU (12/27/88)

    Bernie Cosell suggests:

    How about instead of 3-way calling you simply get "call forwarding" and
    forward all calls to your outgoing lines to some nonexistent place (maybe
    back to your incoming trunks :-).

Call-forwarding loop-prevention provides a means to break this approach.
If the hacker has a line in your central office (same machine), the
"set-up" call for call-forwarding FROM HIS line will ring through on your
already-forwarded line.

And all of this is silly if your hacker is tapping the line and listening with
his hayes in ham mode.  Encryption is the *only* way to go.