Showing papers in "Cryptologia in 1989"
TL;DR: A function based on chaos theory for generating sequences of random numbers to be used like a one-time pad, but the cycle length turns out to be unpredictable and often short.
Abstract: Matthews [1] has proposed a function based on chaos theory for generating sequences of random numbers to be used like a one-time pad. When implemented on digital computer systems, these functions must produce repeating cycles of values. The cycle length turns out to be unpredictable and often short. The function is not suitable for cryptographic use in the manner proposed by Matthews.
127 citations
TL;DR: This document is a brief synthesis on this large subject where randomness and redundancy play the major roles, mainly in integrity techniques: identification, authentication and signature.
Abstract: In December 1984, under reference ISO/TC97/SC20/N42, a Technical Report has been published relating the state-of-the-art of public-key cryptosystems: various comments were sent to WG2, the ISO Working Group dedicated to public-keys; major results have since been published. This document is a brief synthesis on this large subject where randomness and redundancy play the major roles, mainly in integrity techniques: identification, authentication and signature.
10 citations
TL;DR: This paper contains little known vignettes in the life of Herbert O. Yardley which include the Cipher Bureau he established in New York, William F. Friedman, publication of The American Black Chamber, his work for the Canadian government, and an effort to clear his name with the FBI.
Abstract: This paper contains little known vignettes in the life of Herbert O. Yardley which include the Cipher Bureau he established in New York, William F. Friedman, publication of The American Black Chamber, his work for the Canadian government, an effort to clear his name with the FBI, and a secret investigation of his loyalty by the Army's Counter Intelligence Corps during World War II.
5 citations
TL;DR: This article reports the last of a series of experiments performed between 1984 and 1988 to explore the limits of artificial intelligence techniques in the automated solution of ciphers in crypt-text-only attacks.
Abstract: This article reports the last of a series of experiments performed between 1984 and 1988 to explore the limits of artificial intelligence (AI) techniques in the automated solution of ciphers in crypt-text-only attacks. We started with simple substitution ciphers and went on to solve polyalphabetic ciphers, geometric transposition ciphers, and product ciphers that combined the last two techniques.
5 citations
TL;DR: The HC-9 ciphering machine was used in Sweden after World War II and satisfied the need for a simple key-setting process and the requirement of resistance to cryptanalysis by reduction of the risk of error when operated.
Abstract: The HC-9 ciphering machine was used in Sweden after World War II. It satisfied the need for a simple key-setting process and the requirement of resistance to cryptanalysis by reduction of the risk of error when operated. The machine uses a punched card system instead of pin wheels and a drum with 16 changeable mixed alphabets which interrelated with the card reading mechanism and rotates after each letter is enciphered. The enciphering/deciphering process is described along with the machine's operating principles.
4 citations
TL;DR: Great Britain and the United States seek a closer relationship between their cipher experts and Churchill admits decrypting America's diplomatic codes.
Abstract: Great Britain and the United States seek a closer relationship between their cipher experts and Churchill admits decrypting America's diplomatic codes.
4 citations
TL;DR: A simple rotor device is described which can generate two levels of encryption security: periodic encryption to any key length, and random-key encryption.
Abstract: A simple rotor device is described which can generate two levels of encryption security: periodic encryption to any key length, and random-key encryption. The latter depends on what appears to be a useful and widely-available source of at least pseudorandom numbers: the telephone directory.
4 citations
TL;DR: Intercepted and solved, the Japanese MAGIC-ULTRA messages provided Anglo-American intelligence with eyewitness accounts of conditions in the German capital while it was caught between the advancing fronts and lay under Russian siege.
Abstract: The Japanese ambassador in Berlin sent detailed enciphered military, political, and economic reports to his government in Tokyo during the Second World War, but from January 1945 until the end of war in Europe, his reports focused on the destruction of the great metropolis of Berlin. Intercepted and solved, the Japanese MAGIC-ULTRA messages provided Anglo-American intelligence with eyewitness accounts of conditions in the German capital while it was caught between the advancing fronts and lay under Russian siege.
3 citations
TL;DR: This paper shows how a single message in the Gromark cipher, a system which uses a pseudo-random decimal key, can be broken, and investigates some variations of the basic scheme and the properties of the keys.
Abstract: This paper shows how a single message in the Gromark cipher, a system which uses a pseudo-random decimal key, can be broken, and investigates some variations of the basic scheme and the properties of the keys.
TL;DR: A cryptanalyst's training in this country and in England; his experiences in the European Theater of Operations, and his preparation for the Japanese conflict are discussed in this article, where references are made to Herbert O. Yardley, John M. Manley, and William F. Friedman.
Abstract: A cryptanalyst's training in this country and in England; his experiences in the European Theater of Operations, and his preparation for the Japanese conflict. References are made to Herbert O. Yardley, John M. Manley, and William F. Friedman.
TL;DR: A matrix based cipher is presented and it is shown that it is equivalent to a Variant Beaufort cipher using a non-standard arithmetic and placed in historical perspective not only from the point of view of cryptography but also in regard to the state of mathematics in England in the middle of the nineteenth century.
Abstract: A diary entry of Charles L. Dodgson, better known as Lewis Carroll, indicates that he invented two polyalphabetic ciphers in 1858. He published neither of them. In this paper we present one, a matrix based cipher, and show that it is equivalent to a Variant Beaufort cipher using a non-standard arithmetic. This is placed in historical perspective not only from the point of view of cryptography but also in regard to the state of mathematics in England in the middle of the nineteenth century. The authors have written a computer program that can be used to explore this and similar ciphers.
TL;DR: A versatile and simple method to strengthen one-to-one enciphering transformations is presented, which can be an alternative way to superenciphering and stream encipherment and is particularly suited to digital implementation, both in software and in hardware.
Abstract: A versatile and simple method to strengthen one-to-one enciphering transformations is presented. This method, which can be an alternative way to superenciphering and stream encipherment, has some interesting properties and is particularly suited to digital implementation, both in software and in hardware.
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TL;DR: This article is an exposition of a pencil and paper cipher used by Soviet secret agents working inside the U. S. that successfully defied the government's computer-aided attempt at cryptanalysis for several years.
Abstract: This article is an exposition of a pencil and paper cipher used by Soviet secret agents working inside the U. S. that successfully defied the government's computer-aided attempt at cryptanalysis for several years.
TL;DR: Character strings consisting of written language can be distinguished from other strings of characters as long as characters are correctly assigned to a number of single groups of known identity.
Abstract: Character strings consisting of written language can be distinguished from other strings of characters. Not all characters occurring in the text need be utilized to accomplish this. Respectable results can be obtained using about half the characters occurring in the text. Initially it is not even necessary to know the individual identity of any character as long as characters are correctly assigned to a number of single groups of known identity.
TL;DR: The encoding method proposed here is designed for manual implementation in a tactical setting or an asymmetric setting, and eliminates ambiguity by combining three encoding systems to form a single concatenated codeword.
Abstract: In this paper, various methods of encoding Chinese characters are presented. The encoding problem is unique, because unlike English, Chinese has no alphabet; there is no real order to the thousands of characters. The encoding method proposed here is designed for manual implementation in a tactical setting (where no dictionary is allowed) or an asymmetric setting (where only a decoding dictionary is allowed). Each Chinese character has three units of information: tone, shape, and phonetic. Most traditional encoding methods only take into account one or two of these units, and are therefore ambiguous. Many of these methods are unsuitable for other reasons as well - requiring lengthy codebooks, specialized language training, etc. The method proposed here eliminates ambiguity by combining three encoding systems to form a single concatenated codeword. Tone is encoded with a single digit, shape with the Four Corner system, and Phonetic with the Chinese National Phonetic Alphabet. This method also satisfies othe...
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TL;DR: A personalized account of the 30-year service as a cryptanalyst with the National Security Agency and its predecessors, emphasizing the World War II period, with reference to certain Japanese and German systems.
Abstract: A personalized account of the 30-year service as a cryptanalyst with the National Security Agency and its predecessors, emphasizing the World War II period, with reference to certain Japanese and German systems. Other ciphers are mentioned in nonspecific terms. The thrust of the argument is that the U.S. government might well release an “approved” and controllable version of our success, rather than fret about half-truths that appear in stories from less authentic and possibly uncontrollable sources.
TL;DR: An extension of the Morris Known Plaintext Attack is shown to permit complete cryptanalysis of a generalized Hagelin (M-209) cipher machine implemented electronically and modifications of the encrypting algorithm are suggested to defeat the attack.
Abstract: An extension of the Morris Known Plaintext Attack is shown to permit complete cryptanalysis of a generalized Hagelin (M-209) cipher machine implemented electronically. We then suggest modifications of the encrypting algorithm to defeat the attack.
TL;DR: (1989).
Abstract: (1989). VIET CONG SIGINT AND U.S. ARMY COMSEC IN VIETNAM. Cryptologia: Vol. 13, No. 2, pp. 143-150.
TL;DR: Charles L. Dodgson, better known as Lewis Carroll, invented several polyal-phabetic ciphers by 1868 and the two that he published are put into historical perspective in this paper.
Abstract: Charles L. Dodgson, better known as Lewis Carroll, invented several polyal-phabetic ciphers by 1868. The two that he published are put into historical perspective in this paper. His Alphabet Cipher produces a Vigenere enciphered text, while his Telegraph Cipher is equivalent to a Beaufort cipher. In constructing the Telegraph Cipher, Dodgson used two sliding alphabets, similar to the St. Cyr slide invented by Auguste Ker-ckhoff fifteen years later. A program is available to explore these ciphers and another, the Variant Beaufort.