Abstract: | The degree of sophistication available in today's programmable personal calculators may be used to provide a practical field cipher capability of significant power. Procedures are presented for key management, key generator cycling alarm, cipher-type selection to match cryptanalytic threat level, and key length options as an answer to key-search attacks. Three basic cipher procedures are presented with special emphasis given to the inherent power of transposition techniques. Four cryptogram examples are included to demonstrate four of the levels of available security offered by the system. |