A POLYGRAPHIC SUBSTITUTION CIPHER BASED ON MULTIPLE INTERLOCKING APPLICATIONS OF PLAYFAIR |
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Authors: | DOUGLAS W MITCHELL |
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Affiliation: | Department of Computer Science , Royal Holloway College , Egham, Surrey, TW20 OEX, ENGLAND |
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Abstract: | This paper presents a non-numerical polygraphic substitution cipher which appears more efficient than Hill's algebraic system. For instance, by using the same number of “operations” per message as a 6-graphic algebraic substitution cipher, the present cipher can achieve 4096-graphic substitution. Less dramatically, a 16-graphic application of the present cipher requires only one-eighth as many operations as a 16-graphic algebraic cipher. The source of the greater efficiency of the proposed cipher is that the number of letters which can be jointly enciphered is exponential, rather than linear, with respect to the number of operations performed. |
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Keywords: | polygraphic substitution multiple interlocking Playfair algebraic cipher efficiency advantage |
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