Finding the key length of a Vigenère cipher: How to improve the twist algorithm

Abstract

A Vigenère cipher applies a single short key repeatedly to encrypt a plaintext. If a cryptanalyst correctly finds out the key length, the ciphertext can be divided into multiple instances of shift cipher and be broken by frequency analysis. To determine the key length, the twist algorithm, an alternate method to the standard Kasiski and Friedman tests, was recently proposed. In this article, we propose the twist⁺ algorithm, an improved twist algorithm, which can estimate the key length more accurately than the original twist algorithm.     

Cryptanalysis of an asymmetric cipher protocol using a matrix decomposition problem一个基于矩阵分解的非对称密码协议的分析

Advances in quantum computation threaten to break public key cryptosystems such as RSA, ECC, and ElGamal that are based on the difficulty of factorization or taking a discrete logarithm, although up to now, no quantum algorithms have been found that are able to solve certain mathematical problems on noncommutative algebraic structures. Against this background, Raulynaitis et al. have proposed a novel asymmetric cipher protocol using a matrix decomposition problem. Their proposed scheme is vulnerable to a linear algebra attack based on the probable occurrence of weak keys in the generation process. In this paper, we show that the asymmetric cipher of the non-commutative cryptography scheme is vulnerable to a linear algebra attack and that it only requires polynomial time to obtain the equivalent keys for some given public keys. We also propose an improvement to enhance the scheme of Raulynaitis et al.     

Cryptanalysis of enhancement on “quantum blind signature based on two-state vector formalism”

Recently, Yang et al. (Quantum Inf Process 12(1):109, 2013) proposed an enhanced quantum blind signature based on two-taste vector formalism. The protocol can prevent signatory Bob from deriving Alice’s message with invisible photon eavesdropping attack or fake photon attack. In this paper, we show that the enhanced protocol also has a loophole that Alice can utilize an entanglement swapping attack to obtain Bob’s secret key and forge Bob’s valid signature at will later. Then, we reanalyze two existing protocols and try to find some further methods to fix them.     

Internet technology in support of the concept of “communities-of-practice”: the case of Xerox

Work practices usually differ fundamentally from the way that organizations describe their operations in manuals, training programs, etc. This paper focuses on the way that certain work practices are supported at Xerox, and the conclusions of this effort are related to complementary investigations on learning and innovation. Here we propose that the combination of work, learning and innovation should be reconsidered within the framework of informal “communities-of-practice.” Information Technology tends to be used in order to reinforce the old work and study paradigms. This paper suggests a different use of IT, a use especially well suited to intra- and internets, with the aim of supporting informal structures rather than formal procedures. The case of Xerox Corporation is used as an example.     

Breaking the walls of social exclusion of women rural by means of ICTs: The case of ‘digital divides’ in Galician

This paper examines the digital divides for women in rural areas within the Information Society, referring particularly to the Galician experience (Autonomous Region in the North West of Spain). In order to explore the barriers to social and labor exclusion it was elaborated a survey relating with the use and impact of ITC in social and labor experiences of rural women. The results showed that rural women are aware of the key role played for ITC on their way to achieve the participation on decision making process as well as in social life and labor. The main barriers to the Internet penetration in women social life were employment, education and income. From an individual point of view, the existence of non-users was explained by a combination of access problems, lack of ICT skills or rather negative attitudes towards ITC. Finally, a bunch of policy recommendations is proposed focus on providing better Internet access in rural areas and to sensitize the population, particularly the oldest, about the importance of gender equality in access to technology in order to avoid digital barriers for rural women and reduce social exclusion of this group.     

The “Panopticon” of search engines: the response of the European data protection framework

Nowadays, Internet users are depending on various search engines in order to be able to find requested information on the Web. Although most users feel that they are and remain anonymous when they place their search queries, reality proves otherwise. The increasing importance of search engines for the location of the desired information on the Internet usually leads to considerable inroads into the privacy of users. A heated debate is currently ongoing at European level regarding the question if search engine providers that are established outside the European Union are covered by the European data protection framework and the obligations it imposes on entities that process personal data. The scope of this paper is to examine the applicability of the European data protection legislation to non-EU-based search engine providers and to study the main privacy issues with regard to search engines, such as the character of search logs, their anonymisation and their retention period. Ixquick, a privacy-friendly meta-search engine, will be presented as an alternative to privacy intrusive existing practices of search engines.     

An Update of Tarski: Two Usages of the Word “True”

Journal of Logic, Language and Information - This paper is based on Tarski’s theory of truth. The purpose of this paper is to solve the liar paradox (and its cousins) and keep both of the...     

Effects of “gender” of the computer on informational social influence: the moderating role of task type

The present experiment examined if and how “gender” of the computer, manifested in character representation, would affect its informational influence on individuals’ decisions on masculine (sports) or feminine (fashion) topics. In a 2 (participant's gender) ×2 (character gender) ×2 (nature of topic: masculine vs. feminine) between-subjects experiment, participants played a trivia quiz game with the computer. During the game, they were given a chance to change their initial answer after seeing the computer's answer, which they knew was not necessarily correct. Results supported the match-up hypothesis such that while the male computer elicited greater conformity on the masculine topic than on the feminine topic, the opposite was true for the female counterpart. In addition, men were less likely to yield to the computer's suggestion than women on the masculine topic whereas women were less likely to succumb to the computer's influence on the feminine topic. These findings are discussed in terms of the robustness of gender-stereotyping in human–computer interaction and the implications for Computers Are Social Actors paradigm.     

“ExTHERM”: the interactive support package of experimental thermodynamics

The presented program package “ExTHERM” consists of three parts: (i) cETD, a simple interactive open data bank module covering all types of metal alloys (over 150 binary phases and some ternaries), (ii) cMod, a module for algebraic conversion among different representations of excess data, and (iii) cM3_(KMS/ EMF/HTC), three interactive evaluation units suitable for overall best fits of experimental investigations expandable to mass spectrometric (KMS), EMF, and calorimetric investigations (HTC). The concept is based upon the multi-component TAPS ($\text{T}$hermodynamically $\text{A}$dapted $\text{P}$ower $\text{S}$eries) concept of excess quantities covering all types of solutions, includingn liquid alloys showing short range ordering. The data bank is based upon the Hultgren data of binary systems and on new experimental data. Individual supplements may be performed easily. The conversion module employs a modular concept procedure which makes the conversions independent of the actual system data. For all software modules contact the author.     

Variations of anatomical elements contributing to subtalar joint stability: intrinsic risk factors for post-traumatic lateral instability of the ankle?

Ankle sprains are frequently followed by chronic lateral instability, often with talar hypermobility. This might be due to subtalar instability. Among intrinsic risk factors, anatomical variants are generally overlooked. In the subtalar region, anatomical variation is particularly frequent. On the talus as well as on the calcaneus, the anterior articular facets may be missing or fused with the medial facets, giving rise to three subtalar joint configurations: a three-joint configuration, a fused configuration with a relatively large anteromedial joint, and a two-joint configuration without anterior joint. Osteometry was performed on these joint facets (134 calcanei, 122 tali), demonstrating significant differences in the surface of these configurations and the existence of a supplementary supporting surface with grossly transverse orientation in the three-joint configuration. There are also several variants of stabilizing ligaments within the sinus tarsi. Some of these configurations might expose to increased risk of associated subtalar lesions, resulting in subtalar instability. A systematic look for these variants is recommended in order to evaluate the associated risk factors, eventually resulting in a better understanding, prevention and cure of sequellae.     

Breaking news: “I have an eating disorder.” Video testimonials on YouTube

Over the last several decades there has been an exponential increase in the usage of the Internet, and social networking websites in particular. Social networking websites have gained popularity because they allow people to network on both a personal and professional level. The rise of testimonial videos about one’s experience with hardships has gained popularity as another way for people to connect with one another for support. The current study looks at men and women who utilized YouTube, a video posting website, to document their struggles with eating disorders (ED). Fifty videos were viewed and analyzed regarding content and viewer response. It was found that most posters actively sought treatment for their ED, yet sought out additional support on the Internet while also offering support for others. In addition, viewers responded with an overwhelmingly large number of supportive comments compared to negative comments (8:1).     

The metamorphoses of the “Exemplar”

The starting point of this work isthe artificial, as defined in a previous study by Massimo Negrotti and, more completely, in the essay presented here, as a machine which reproduces the essential performance of some natural subsystem that serves as an exemplar, at a chosen level of observation. I assume also Negrotti's distinction between the technology of the artificial and conventional technology. These theoretic assumptions, and the relevant terminology, represent here the starting point for a reflection upon the process of imitating the natural exemplar and ofideating the technological object, and upon the interrelations between these two moments of inventiveness.     

“Breathing the thin air of cyberspace”: Global knowledge and the Nepal context *

Abstract

This article examines global and indigenous knowledge sharing with a focus on electronic information exchange in Nepal's development sector. Drawing on lessons from experience based on two local examples, a framework is presented of a strategy for realising the potential of Information and Communications Technology (ICT) in countries where knowledge sharing and access is constrained in a variety of ways.

The “iCAPACITY framework” outlined for the South Asian context integrates the inter‐dependent themes of Content, Access, and Partnership, highlighting the critical components that require consideration when building the capacity for ICT usage and knowledge sharing in a developing country context. Practical initial steps are put forward, that recognise the primary concern for holistically addressing economic, social and environmental issues, with the overall priority of alleviating poverty using broad‐based participation.

The paper concludes that developing countries such as Nepal, currently occupy what may be metaphorically referred to as “the thin air of cyberspace”, where the essential knowledge needing to be shared locally or globally is not yet widely available or accessible. In this context, particular care has to be taken in formulating localised strategies and models that can improve the quality of this “air”, and lead to a situation where development efforts can truly be enhanced by the IT revolution.     

“Missing women”: Gender,ICTs, and the shaping of the global economy

In a key article (Walsham & Sahay, 2005) outlining research on information systems in developing countries and suggesting potential areas for future research, a notable omission was the issue of gender and gender relations. In this article, we draw on the substantial gender and development literature to demonstrate the centrality of gender to our understanding of information systems (IS) in developing countries. In particular, we consider the relationship among gender, information and communication technologies (ICTs), and globalization to illustrate how changes in the global economy both impact on and are influenced by changing gender identities and roles. © 2008 Wiley Periodicals, Inc.     

“Critic-proofing” of the cognitive aspects of simple games

This paper posits the use of computer games as cognitive development tools that can provide players with transferable skills suitable for learning in the 21st century. We describe a method for categorizing single-player computer games according to the main cognitive function(s) engaged in by the player during gaming. Categorization was done in collaboration with a neuropsychologist, academic researchers, and research assistants. Twelve research assistants, mostly domain novices, were trained to categorize games according to a cognitive matrix developed by the neuropsychologist. They also categorized the games, and evaluated and commented on the relevance of the neuropsychologist's categorization of the games. Through the process of “critic proofing,” computer games were reliably classified into primary and secondary cognitive categories, and the team was able to identify problems with both the categorization of certain games and the definitions of some of the cognitive functions in our cognitive matrix. Such an approach allowed for the identification of under-populated cognitive categories in the project's existing repository of games, and for further development of the cognitive representation framework, information useful for both researchers and designers in the gaming industry.     

Modelling and measuring the axial force generated by tripod joint of automotive drive-shaft

The present paper deals with measurements and models of axial force produced by a tripod joint of an automotive drive-shaft. An automotive drive-shaft consists of a plunging tripod joint close to the gearbox and a fixed ball joint close to the wheel. Both joints are connected by an intermediate shaft. The measurements of axial force are derived from a gauge extensometry sensor placed on an industrial test bench. The ball joint is modeled as a true and perfect spherical link. For the tripod joint, the rollers between the tripod and the tulip ramps are introduced in such a way that their orientation is taken in account. Then, two inverse models are proposed with a constant input velocity and a constant output torque. To start with, an analytical model is proposed; then a more sophisticated model using Adams software is introduced. It is shown that both models are coherent and in good agreement with experimental measurements of axial forces. Since axial forces generate nuisance vibration harshness with shudder in particular, models are used to predict shudder excitation dependence on tulip radius, input torque, shaft rotation speed and Coulomb friction. Finally, the Coulomb friction coefficient is identified in the models.     

Robust Control: A Note on the Response of the Control to Changes in the “Free” Parameter Conditional on the Character of Nature

In this paper an analytical framework similar to a robust control problem was developed for the one-state, one-control variable model to examine the response of the control to changes in the free parameter. However, in contrast to Gonzalez and Rodriguez (2003), the sign multiplying the free parameter in the criterion function of the min–max problem is positive. We find that this set up corresponds to the case where nature is benevolent while the problem posed by Gonzalez and Rodriguez (2003) corresponds to a malevolent nature. We show that for the benevolent case, the solution is a minimum giving way to an ordinary control problem. In addition, the left side of the discontinuity in Gonzalez and Rodriguez (2003) corresponds to the benevolent case.The opinions contained in this note are exclusively of the authors and do not represent either those of the Sociedad Hipotecaria Federal or Bank of Mexico.     

A Review of “I Found it on the Internet: Coming of Age Online”

SUMMARY

This article will address the problems of developing and implementing a federated searching system and the involvement by reference staff expected to use, teach, and promote it. Implementation of federated search usually begins with developing basic technical functionality and then progresses to increased participation by public service librarians and system users in order to refine searching interfaces and content retrieval mechanisms and display. From the reference perspective, some impediments occurred in utilizing the federated search system since reference staff did not participate in the development of the product; since there was resistance to the concept of the product by instructional staff; and since performance inconsistencies and the use of a complex interface hampered functionality. This article will address the evolution of organizational stakeholder participation in the development of the federated search system at the Loyola Notre Dame Library.     

Breaking away from the conventional ‘usability lab’: the Customer-Centered Design Group at Tektronix,Inc.

Abstract

The conventional usability lab is primarily responsible for testing prototypes and products to determine if customers will accept a new design. Often this testing comes too late in the development cycle to allow major design or product changes to occur. In the Customer-Centered Design Group at Tektronix Labs, the usability lab is a small part of our group's involvement in the entire design life cycle of a Tektronix product. We work with design groups to bring the benefits of a usability lab to all phases of design, beginning with understanding our customer's current system and work processes to assessing the competitor's strengths and weaknesses to simulating and evaluating design alternatives. Our ‘lab’ is often on the road; meeting with customers where they work, working with design teams to simulate and prototype designs, and evaluating designs with our customers. To keep in touch with customers and to keep product development focused, we feel a usability group must break down the barriers inherent in a conventional testing suite. By breaking these barriers we can better determine what customers need and how these needs are addressed throughout the entire product life cycle.