Auswahl der wissenschaftlichen Literatur zum Thema „Attributes-based credential“

Abstract A functional credential allows a user to anonymously prove possession of a set of attributes that fulfills a certain policy. The policies are arbitrary polynomially computable predicates that are evaluated over arbitrary attributes. The key feature of this primitive is the delegation of verification to third parties, called designated verifiers. The delegation protects the privacy of the policy: A designated verifier can verify that a user satisfies a certain policy without learning anything about the policy itself. We illustrate the usefulness of this property in different applications, including outsourced databases with access control. We present a new framework to construct functional credentials that does not require (non-interactive) zero-knowledge proofs. This is important in settings where the statements are complex and thus the resulting zero-knowledge proofs are not efficient. Our construction is based on any predicate encryption scheme and the security relies on standard assumptions. A complexity analysis and an experimental evaluation confirm the practicality of our approach.

We study discrimination against immigrants using microlevel data from Switzerland, where, until recently, some municipalities used referendums to decide on the citizenship applications of foreign residents. We show that naturalization decisions vary dramatically with immigrants’ attributes, which we collect from official applicant descriptions that voters received before each referendum. Country of origin determines naturalization success more than any other applicant characteristic, including language skills, integration status, and economic credentials. The average proportion of “no” votes is about 40% higher for applicants from (the former) Yugoslavia and Turkey compared to observably similar applicants from richer northern and western European countries. Statistical and taste-based discrimination contribute to varying naturalization success; the rewards for economic credentials are higher for applicants from disadvantaged origins, and origin-based discrimination is much stronger in more xenophobic municipalities. Moreover, discrimination against specific immigrant groups responds dynamically to changes in the groups’ relative size.

With rapid growth in popularity and use of Internet in academic institutions, the institutions are struggling to keep up with the demand. They need capability to effectively control, monitor and optimize the available bandwidth to ensure good service at optimum cost. This paper has described implementation of Coovachilli and free radius for management of internet bandwidth in academic institutions. During this research, freeware tools such as Freeradius and CoovaChilli have been used to manage Internet bandwidth on a per-user basis based on user credentials. The mechanisms have been used to control bandwidth of Wireless users. Same can be used for wired connections also. When a user tries to connect, the user is redirected to a captive portal under CoovaChilli. There the user provides login and password. Based on the credentials thus provided, CoovaChilli checks identity with the Freeradius. If authorized, the client is allowed access with the bandwidth as mentioned in the profile of the user in WISPr attributes define in Radreply table of Freeradius. When the user is not authorized, CoovaChilli sends an error message. This paper demonstrates that bandwidth can be effectively monitored, managed and optimized by using cost-effective open-source tools in the existing network scenario of the institution.

Many African academic institutions have adopted the use of e-learning systems, since they enable students to learn at their own pace, time, and without restriction to the classroom. However, evidence of usability evaluation of e-learning systems in Africa is mostly lacking in the literature. This paper reports the experimental heuristic evaluation of the e-learning system of a Nigerian University. The objective is to demonstrate the application of expert-based usability evaluation techniques such as Heuristic evaluation for assessing the attributes of existing e-learning systems. The study revealed that while the e-learning systems has strong credentials in terms of support for Web 2.0 activities, good learning content and boasts of useful e-learning features, improvements are necessary in other areas such as interactive learning, assessment and feedback, and quality of learning content. The study adds to the body of extant knowledge in the area of usability evaluation of e-learning systems in African institutions.

Attribute-Based Encryption (ABE) is a basic concept that considers public-key cryptography. Ciphertext-Policy ABE (CP-ABE) is one of the approaches used by ABE for data sharing in the cloud. In CP-ABE scheme, each user’s private key has a set of attributes and then the user decrypts a ciphertext if it holds a matching key. Our proposed system provides an extension to CP-ABE by implementing AES. AES uses a symmetric encryption key algorithm for a same set of keys. Our system provides a higher security through AES because of its complexity and helps in generating the content key . This key is used during the encryption of the original file over the cloud. Our methodology also focuses on deduplication to provide less consumption of cloud storage over the cloud. Another advantage of using this system is to provide an efficient way of data access via access policies for a certain set of credentials.

Purpose This is an exploratory study on consumer information and behaviour towards green, health, local, social and environmental credentials on labels. It focusses on many dimensions of sustainability in the food products that affect consumer choices with a dual purpose: to identify and define “sustainable consumption” behaviour in broad sense and to investigate empirically the factors affecting the real consumption behaviours. The purpose of this paper is to shed light on consumers’ understanding, motivation and use of sustainable labelling in order to understand the role sustainability information plays in the food products market. Design/methodology/approach Two focus groups in order to investigate consumer motivation and behaviour in-depth and to prepare the questionnaire. Identification of the outcomes that could summarize sustainable consumption combining: purchase of local products, consume only seasonal fruit, prefer products with recyclable packaging, attention to the fat content in foods, give importance to traceability and purchase products only in the place of origin. Identification of the “at risk” virtuous consumer, using a binary logistic regression approach, taking into account demographic characteristics, the food and nutrition value system, experience, knowledge, institutional factors and marketing. Findings Results from the focus groups are mainly in line with the empirical analysis, highlighting the key role of education in influencing consumer attitude and behaviour. Consumers give little attention to information provided on the label for sustainable food consumption and environmental protection and have little knowledge of environmental problems. The virtuous consumer appears to give importance to a better food nutrition value system, to pay more attention to ingredients and instructions on the label, to be more attentive to environmental and sustainable attributes, to be concerned about product quality and to be slightly influenced by brands and special offers. Research limitations/implications The findings from the empirical analysis confirm the results from focus groups even if it was not possible from the empirical analysis to investigate in-depth the marketing aspects concerning the food choice. This limit probably comes from the low number of observations. Further research will focus on these marketing aspects. Practical implications Products with sustainable attributes can become a strategic variable and allow companies to gain a competitive advantage, especially for small- and medium-sized enterprises. This may encourage the development of new marketing channels based on the direct relationship between producer and the new consumer demand, increasingly sensitive to the food security issues. Social implications There is a potential interest and sensitiveness to having sustainable behaviour in a broad sense, but there is a lack of knowledge about how to behave to be sustainable. In the absence of binding rules, it is necessary that government promote information and campaigns to generate greater awareness on sustainability, aiming at increasing knowledge to drive the consumer’s choices. This may lead to virtuous results in terms of reducing social costs related to an unhealthy diet, food waste and unsustainable consumption. Originality/value The results show that despite the appearance of attention to the environment and to healthy food which is associated with this emerging critical consumer in the literature, there remains the problem of the consumer giving little attention to information provided on the label for sustainable food consumption and environmental protection. This is the problem of “rules of thumb” in purchasing decisions that prevail in the following situations: when consumers have an overload of information that exceeds their processing limits; when they tend to base their decision making on heuristics, focussing their choices on brands as a proxy for high-quality, product-related characteristics.

A federation is usually an alliance of organisations where users from one organisation are trusted to access resources in another organisation. The membership of federations is diverse and continually changing. Federations require distributed and dynamic security policy management to meet these challenges. We propose an authorisation policy management model, FABACD, which simplifies the management of collaborations between organisations. It allows distributed and trusted administrators to adjust the authorisation policies in a resource holding organisation, whilst ensuring that the latter remains in ultimate control. The net result is that a resource’s authorisation system is able to use user credentials built from preexisting attributes issued by any participating organisation, in order to determine a user’s access rights to the various resources, without requiring credentials to be issued that are based on federation specific attributes. The model significantly simplifies the authorisation management process for the resource holding organisation.

PurposeInternational student employability has been accorded increased emphasis in the internationalisation agendas, especially in major destination countries as it shapes universities' attractiveness to prospective international students. Having insights into returning graduates' employability in their home country has become critical given that a majority of international graduates return home after their overseas study. This study responds to this critical need by examining how foreign credentials are valued by employers in the field of accounting in China, based on in-depth interviews with employers, alumni and policymakers.Design/methodology/approachThis study draws on a qualitative approach involving literature review and in-depth interviews with 28 key stakeholders: employers, returning graduates and policymakers in China and India. The key research question of the study is how foreign credentials are valued by employers in the field of accounting in China and India. This article focuses on the Chinese context. In-depth interviews with employers and policymakers focused on eliciting nuanced socio-cultural understandings as to perceptions and decisions associated with desirable graduate attributes and the relative value of credentials. Interviews with returning graduates aimed to understand how different capitals were mobilised to gain employment in the Chinese labour market.FindingsThe empirical findings of the study show that Chinese returning graduates could be seen to lack the localised knowledge needed to work in Chinese companies and ability to adapt to the local environment. However the possible development of a dual local and international guanxi through overseas study can be regarded as a marker of distinction in the home labour market. The associated value of such a dual guanxi signals the importance for Chinese international students to develop transnational networks while simultaneously maintaining their kinship, social and business networks locally during their overseas education.Originality/valueThe study provides fresh insights into a marked shift in China, with less of a preference for Western credentials, as compared to 10 years ago when overseas credentials were often regarded more favourably. Even though overseas study generally provides Chinese graduates with an exposure to international practices and global perspectives, whether such an overseas exposure and foreign language competency would be an advantage also depends on the business needs and sometimes the business model of organisations.

This thesis deals with the topic of attribute based credentials with revocable anonymous credentials. The main focus of this work is the implementation of this scheme through a web application. The web application serves primarily as a visualization, which shows the functionality of this scheme through animations, and also as a practical demonstrator. Data and cryptographic calculations for individual system protocols are provided by the given cryptographic C application that communicates with the created application. The web application is also able to communicate with the connected smart card reader and the MultOS smart card and thus create the transmission of APDU commands and responses between the smart card and provided C application.