"monoalphabetically" - 1 õppematerjal

TheCodeBreakers

Thus a Kasiski examination sifts out the  identically keyed letters in a repeating key. A running key with a coherent text can be solved by reciprocally reconstructing the plaintext and the keytext. A running key with a random text used in two or more messages succumbs to a simultaneous reconstruction of the two plaintexts, one checking the other. Other polyalphabetics, such as the autokey and the two-tape system, engender specialized solutions that stem from their own peculiarities. The monoalphabetically enciphered letters that are the goal of these techniques also exist in a Vernam one- time system cryptogram because the 32 available cipher alphabets are used over and over again. But the cryptanalyst has no way of sorting them out because the key in a one-time system neither repeats, nor recurs, nor makes sense, nor erects internal frameworks. Hence, his methods, all based in one way or another on these characteristics, all fail. The perfect randomness of the one-time system nullifies any