"Time for a 2 factor system where the hacker on the other end of the phone doesn't have easy access to one of the factors. "
this is where dial-backs come in handy .
the way it works is :
1 you get a call from "Joe Smith in the Texas Office"
2 you tell "Joe" im going to dial you back give me Line 3 when i call
3 you use your phone list to dial him back and
4 Joe gives you Line 3 (this is from a key string list) AND You as instructed give him line "5"
5 You then continue with business
Or Video Phones with the system doing Face Recog on both persons