  The idealized Kish-Sethuraman (KS) cipher is theoretically known to offer
perfect security through a classical information channel. However, realization
of the protocol is hitherto an open problem, as the required mathematical
operators have not been identified in the previous literature. A mechanical
analogy of this protocol can be seen as sending a message in a box using two
padlocks; one locked by the Sender and the other locked by the Receiver, so
that theoretically the message remains secure at all times. We seek a
mathematical representation of this process, considering that it would be very
unusual if there was a physical process with no mathematical description and
indeed we find a solution within a four dimensional Clifford algebra. The
significance of finding a mathematical description that describes the protocol,
is that it is a possible step toward a physical realization having benefits in
increased security with reduced complexity.
