The CCM is a wire wheeled enciphering machine. Ezicipherment
is through a normal alphabet input, one-way through five
wheels, and through a normal alphabet output. Each side of
each wheel has an even number of notches, from eight to six-
teen. Let us number the wheels 1, 2, 3, 4, 5 from left to
right. The middle wheel (#3) steps every time. Wheel 4
moves under the influence of the notches on the right side
of wheel 3, and wheel 5 under the influence of the notches on
the right side of wheel 4. Similarly, 2 is influenced by the
left notches of 3 and 1 by the left notches of 2. A wheel
steps if and only if a notch of its governing wheel is in the
active position. The five wheels are chosen from a set of
ten and may be inserted straight or in reverse. There are
thus 20 x 18 x 16 x 14 x 12 = 967,680 wheel orders.
For a known wheel order, the attacks are relatively simple
and could be run on a grenade, on Hypo, or by IBM techniques.
No equipment and no mode of attack are known for unknown
wheel orders, at least in any operational sense.