Modular design of information encipherment for computer systems

Abstract The application of Vigenere ciphers to the design of enciphering systems for computer systems is presented. Considerations are based on two theorems which enable the generalization of Vigenere ciphers giving the lower bound on the probability of breaking a key. The application of theorems to the design of an enciphering module, that makes possible, in a simple way, the design of arbitrarily complex enciphering systems is shown. Such modular design easily permits fitting the degree of protection to the requirements of the user. The enciphering process with the use of an enciphering module is compared, qualitatively, with the DES recommended by the U.S. National Bureau of Standards.