Showing papers in "Cryptologia in 1983"
TL;DR: In this paper, a "weaker" PRIVACY PROTOCOL USING the RSA CRYPTO ALGORITHM was proposed. But the RSA algorithm was not used in this paper.
Abstract: (1983). A “WEAK” PRIVACY PROTOCOL USING THE RSA CRYPTO ALGORITHM. Cryptologia: Vol. 7, No. 2, pp. 180-182.
71 citations
TL;DR: This paper proposes a Public Key Cryptosystem using a reciprocal number to break the proposed cryptosystem is proven to be as difficult as factoring a large number.
Abstract: This paper proposes a Public Key Cryptosystem using a reciprocal number. Breaking the proposed cryptosystem is proven to be as difficult as factoring a large number. Encryption requires O(n 2) bit operations and decryption requires O(n 3) bit operations. (n is the bit length of a plaintext.)
29 citations
TL;DR: The surprising discovery that information can be passed both covertly and legally between bridge partners has added a new dimension to the theory of this popular game.
Abstract: The surprising discovery that information can be passed both covertly and legally between bridge partners has added a new dimension to the theory of this popular game. In this paper some of the methods are sketched and their cryptologic foundation is described.
26 citations
TL;DR: Using the eight parity bits of the DES key to select from 256 alternative sets of substitution (S-) boxes increases key space from 256 to 264, permits operating in an autokeying mode if desired, and allows up to $\left(\matrix{65,536 \cr 8,192}\right) variants of the algorithm.
Abstract: Using the eight parity bits of the DES key to select from 256 alternative sets of substitution (S-) boxes increases key space from 256 to 264, permits operating in an autokeying mode if desired, and allows up to $\left(\matrix{65,536 \cr 8,192}\right) variants of the algorithm. We employ multi-level binary derivative sequences to show that our S-boxes scramble the bits of crypt-text as well as unmodified DES does.
12 citations
TL;DR: In this paper, the authors describe how to use the German ENIGMA CIPHER MACHINE: A PHOTOGRAPHIC ESSAY, with a focus on the German Enigma Ciphers.
Abstract: (1983). HOW TO USE THE GERMAN ENIGMA CIPHER MACHINE: A PHOTOGRAPHIC ESSAY. Cryptologia: Vol. 7, No. 4, pp. 291-296.
9 citations
TL;DR: This paper investigates two DES-based hashing methods and it is shown that neither method seems to introduce any statistical regularities in the generated checksums.
Abstract: Secrecy and authentication are two important features of a secure communication system. Public Key Cryptosystems, based, e.g., on the Rivest-Shamir-Adleman (RSA) algorithm, provide a very elegant solution to the problem of authenticity verification or true electronic signatures. Practical problems, however, mainly the lack of execution speed, prevent a straightforward application. In order to sign a long message it is much faster to first calculate a short digest or checksum and then sign the compressed message. For this checksum calculation the fast, inexpensive and extensively tested Data Encryption Standard (DES) can be used. But care must be taken that this additional processing step does not introduce any weakness into the signature scheme. This paper investigates two DES-based hashing methods. It is shown that neither method seems to introduce any statistical regularities in the generated checksums. The “Cipher/Message to Plain Feedback,” however, is not secure under a modification compensation atta...
9 citations
TL;DR: A modification of the cage of the Hagelin (M-209) cipher machine is shown to make the modified cipher secure against the Morris Known Plaintext Attack.
Abstract: A modification of the cage of the Hagelin (M-209) cipher machine is shown to make the modified cipher secure against the Morris Known Plaintext Attack.
8 citations
TL;DR: A public-key cryptological method based upon a relation like c =- m modulo r where e and r are not known by anyone but the intended receiver of the messages, which works with polynomials over finite fields.
Abstract: The present paper describes a public-key cryptological method based upon a relation like ${\rm c} \mathop = \limits_{-} {\rm m}^{{\rm e}} modulo r where e and r are not known by anyone but the intended receiver of the messages. This is in contrast to the well known method denoted RSA after the introducers Rivest, Shamir and Adleman. Instead of working with very large natural numbers the method as described here works with polynomials over finite fields. How to compute c from m without knowing e and r is described and a very simple case is worked out in some detail
7 citations
TL;DR: The limitations for applying unicity point arguments in cryptology are discussed and bounds for the redundancy of written German are calculated.
Abstract: This paper is a continuation of [8]. The limitations for applying unicity point arguments in cryptology are discussed. In addition bounds for the redundancy of written German are calculated.
5 citations
TL;DR: A cipher based on word block lengths interpreted as base N numbers, and converted to base M numbers is described, with the advantage is that the ciphertext length can be chosen to be greater or less than the plaintext length, even though word divisions are maintained.
Abstract: A cipher based on word block lengths interpreted as base N numbers, and converted to base M numbers is described. The advantage is that the ciphertext length can be chosen to be greater or less than the plaintext length, even though word divisions are maintained. This gives a very high resistance to Probable Word searches. In its simplest form, however, the number of possible keys is limited, reducing the security of the cipher once the basis is guessed.
TL;DR: A Failure of Radio Intelligence: An Episode in the Battle of the Coral Sea as mentioned in this paper is an episode in the history of radio intelligence in the military domain, which is a classic example of radio failure.
Abstract: (1983). A Failure of Radio Intelligence: An Episode in the Battle of the Coral Sea. Cryptologia: Vol. 7, No. 2, pp. 97-118.
TL;DR: This paper presents a meta-modelling study of the early models of the T52 chimpanzee and halske machine and some of the assumptions made in that study are explained.
TL;DR: As a professional cryptanalyst, I couldn't resist the urge to attack the unknown cipher which appeared in Dr. Brent Morris's article, "Fraternal Cryptography", and set out with paper and pencil in hand to try to remedy that situation.
Abstract: As a professional cryptanalyst, I couldn't resist the urge to attack the unknown cipher which appeared in Dr. Brent Morris's article, \"Fraternal Cryptography\" (Cryptologic Spectrum, Summer 1978). The unusual cipher (supposedly Masonic in nature) with its exotic-looking forms was said to have been part of a manuscript written in 1827 by one Robert Folger of New York. As no recorded solution of Folger's cipher appeared to exist, I set out with paper and pencil in hand to try to remedy that situation. Initially a number of assumptions about the cipher had to be made. Some could be justified, others could not. The assumptions I made were as follows: • That the underlying plain language is English a logical assumption as the creator of the cipher lived in New York and had an English-sounding surname. • That the orientation of the sample page of cipher is correct as shown, with the cipher text reading from top to bottom and from left to right. This would be expected for normal English plain text. Additionally a paragraph appears to end in the middle of the second line of cipher text. The third line likely begins a new paragraph as indicated by the indentation of the line and the illustration or illumination of its first few characters.
TL;DR: In this article, the VIEM from ACROSS THE POND AN INTERVIEW with the GENEVA MANAGEMENT GROUP is described. But it is not discussed in detail.
Abstract: (1983). THE VIEM FROM ACROSS THE POND AN INTERVIEW WITH THE GENEVA MANAGEMENT GROUP. Cryptologia: Vol. 7, No. 2, pp. 187-190.
TL;DR: In this paper, an empirical method, based on regression analysis of frequency counts from a sample of ciphertexts, which is more reliable, yet easier to use, is described.
Abstract: Finding the keylength is the essential step in breaking periodic substitution ciphers. However, the well-known Index of Coincidence technique becomes less reliable as the keylength increases. We describe an empirical method, based on regression analysis of frequency counts from a sample of ciphertexts, which is more reliable, yet easier to use.
TL;DR: The needs for security of information in Western Europe are seen as being significantly different from the needs in the United States, and the official and unofficial attitudes towards policy and regulation of information security technology (particularly cryptology) are described.
Abstract: The needs for security of information (in computer systems, on telecommunications and on media) are rather uniform throughout Western Europe, and are seen as being significantly different from the needs in the United States. Recognition of these needs is, however, quite varied; attitudes towards the best methods for satisfying the needs are even more varied. The situation with respect to these needs and attitudes is described for the major countries of Western Europe. The official and unofficial attitudes towards policy and regulation of information security technology (particularly cryptology) is also described for these countries. In particular, it is clear that, with a very few exceptions, neither official nor unofficial policy level organizations are prepared to follow the position advocated by the U.S. Government in such matters.
TL;DR: If P is a plaintext matrix, over Z/29 and P is embedded into an infinite matrix in the way described in this paper, then enciphering and deciphering can be carried on in a way similar to that in the Hill system.
Abstract: In this paper, a class of infinite matrices called “R.D.” class is introduced. Each member of this class is an infinite matrix K (over Z/29) which admits the existence of an infinite number of matrices ${\overline {\rm K}}_{\rm i} (i=1,2,3,…) satisfying {\overline {\rm K}}_{\rm i}{\rm K}={\rm I} (
eq {\rm K}{\overline {\rm K}}_{\rm i}), where each ${\overline {\rm K}}_{\rm i} is over Z/29. If P is a plaintext matrix, over Z/29 and P is embedded into an infinite matrix in a way described in this paper, then enciphering (using ${\overline {\rm K}}_{\rm i} for any i) and deciphering (using K) can be carried on in a way similar to that in the Hill system ([2],[3]). Security and freedom are thus increased at no cost since the deciphering algorithm uses the same K while the enciphering algorithm can use any of the ${\overline {\rm K}}_{\rm i} (i=1,2,3,…). To increase security (and other objectives) the entries of each member of this class are required to be functions of several parameters λ μ,,…. Moreover, som...
TL;DR: A back-tracking pruning method is described which allows rapid key determination using a known plaintext attack when the DES algorithm is restricted to two rounds.
Abstract: A back-tracking pruning method is described which allows rapid key determination using a known plaintext attack when the DES algorithm is restricted to two rounds.
TL;DR: A BASIC program which automates the probable plaintext solution of Beaufort ciphers is discussed and illustrated.
Abstract: A BASIC program which automates the probable plaintext solution of Beaufort ciphers is discussed and illustrated.
TL;DR: Control features have been implemented in ROTERM which permit keyboard and/or remote control of the encipherment and decipherment of ASCII character strings.
Abstract: Microprocessors are playing an increasingly important role in cryptographic systems. ROTERM is an implementation of a cipher terminal using an inexpensive microcomputer system. ROTERM behaves like a mechanical rotor system of eight rotors with 96 elements each. Control features have been implemented in ROTERM which permit keyboard and/or remote control of the encipherment and decipherment of ASCII character strings. Examples are given demonstrating the use of ROTERM in user-user communications as well as user-electronic mail system posting and reading of messages.