A cryptographic system having a plurality of rotors or electronic equivalents using displacement tables. A rotor movement controller, in accordance with a rotor selection value, selectively moves one or more of the rotors or the electronic equivalent of the rotors for each data input value. Contiguous rotor selection values have a triangle or sawtooth shape. A key-driven displacement look-up table randomizes the selection values. The rotor wirings or displacement tables each have N displacement values. The N displacement values are one to N−1 inclusive once and N/2 twice and arranged in a sequence that forms a single loop. Additionally, the N displacement values may be arranged in a sequence that is self-reciprocal so that no change in the rotors or displacement tables is needed whether encrypting or decrypting except for selectively adding a factor of N/2 when indexing the displacement tables or setting the initial position of the rotors.