. "co-invented" . . . . "One-time pad" . . . "usual disadvantages of one-time pads" . . "make this scheme secure" . "One-time pad" . . . . . . "cannot be broken" . . . "one-time-pad" . . "one-time pad" . "pads" . "one-time-pad encryption" . . "one-time tape" . . "one-time cipher pads" .