889 resultados para Group identity - Turkey
Resumo:
Distributed-password public-key cryptography (DPwPKC) allows the members of a group of people, each one holding a small secret password only, to help a leader to perform the private operation, associated to a public-key cryptosystem. Abdalla et al. recently defined this tool [1], with a practical construction. Unfortunately, the latter applied to the ElGamal decryption only, and relied on the DDH assumption, excluding any recent pairing-based cryptosystems. In this paper, we extend their techniques to support, and exploit, pairing-based properties: we take advantage of pairing-friendly groups to obtain efficient (simulation-sound) zero-knowledge proofs, whose security relies on the Decisional Linear assumption. As a consequence, we provide efficient protocols, secure in the standard model, for ElGamal decryption as in [1], but also for Linear decryption, as well as extraction of several identity-based cryptosystems [6,4]. Furthermore, we strenghten their security model by suppressing the useless testPwd queries in the functionality.
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We introduce the notion of distributed password-based public-key cryptography, where a virtual high-entropy private key is implicitly defined as a concatenation of low-entropy passwords held in separate locations. The users can jointly perform private-key operations by exchanging messages over an arbitrary channel, based on their respective passwords, without ever sharing their passwords or reconstituting the key. Focusing on the case of ElGamal encryption as an example, we start by formally defining ideal functionalities for distributed public-key generation and virtual private-key computation in the UC model. We then construct efficient protocols that securely realize them in either the RO model (for efficiency) or the CRS model (for elegance). We conclude by showing that our distributed protocols generalize to a broad class of “discrete-log”-based public-key cryptosystems, which notably includes identity-based encryption. This opens the door to a powerful extension of IBE with a virtual PKG made of a group of people, each one memorizing a small portion of the master key.
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This paper surveys the practical benefits and drawbacks of several identity-based encryption schemes based on bilinear pairings. After providing some background on identity-based cryptography, we classify the known constructions into a handful of general approaches. We then describe efficient and fully secure IBE and IBKEM instantiations of each approach, with reducibility to practice as the main design parameter. Finally, we catalogue the strengths and weaknesses of each construction according to a few theoretical and many applied comparison criteria.
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Cinema is central to the mediation of history and the construction of imaginative geographies that offer a politicized view of the land and its people. This article investigates cinematic representations of landscape and analyses the ways in which maps and journeys in Charles Chauvel’s film Jedda (1955) and Baz Luhrmann’s Australia (2008)—both set in the far North of Australia—articulate conceptions of “Australianness” in relationship to Indigeneity and the land. We argue the exotic tropics and arid outback regions of northern Australia function metonymically as representative of the nation in these films, working to naturalize ideological values and affirm dominant narratives of history, identity, and entitlement.
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Phishing is deceptive collection of personal information leading to embezzlement, identity theft, and so on. Preventive and combative measures have been taken by banking institutions, software vendors, and network authorities to fight phishing. At the forefront of this resilience are consortiums such as APWG (Anti-Phishing Working Group) and PhishTank, the latter being a collaborative platform where everyone can submit potentially phishing web-pages and classify web-pages as either phish or genuine. PhishTank also has an API that the browsers use to notify users when she tries to load a phishing page. There are some organizations and individuals who are very active and highly accurate in classifying web-pages on PhishTank. In this paper, we propose a defense model that uses these experts to fight phishing.
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User evaluations using paper prototypes commonly lack social context. The Group simulation technique described in this paper offers a solution to this problem. The study introduces an early-phase participatory design technique targeted for small groups. The proposed technique is used for evaluating an interface, which enables group work in photo collection creation. Three groups of four users, 12 in total, took part in a simulation session where they tested a low-fidelity design concept that included their own personal photo content from an event that their group attended together. The users’ own content was used to evoke natural experiences. Our results indicate that the technique helped users to naturally engage with the prototype in the session. The technique is suggested to be suitable for evaluating other early-phase concepts and to guide design solutions, especially with the concepts that include users’ personal content and enable content sharing.
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User-generated content plays a pivotal role in the current social media. The main focus, however, has been on the explicitly generated user content such as photos, videos and status updates on different social networking sites. In this paper, we explore the potential of implicitly generated user content, based on users’ online consumption behaviors. It is technically feasible to record users’ consumption behaviors on mobile devices and share that with relevant people. Mobile devices with such capabilities could enrich social interactions around the consumed content, but it may also threaten users’ privacy. To understand the potentials of this design direction we created and evaluated a low-fidelity prototype intended for photo sharing within private groups. Our prototype incorporates two design concepts, namely, FingerPrint and MoodPhotos that leverage users’ consumption history and emotional responses. In this paper, we report user values and user acceptance of this prototype from three participatory design workshops.
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Guitar technology underwent significant changes in the 20th century in the move from acoustic to electric instruments. In the first part of the 21st century, the guitar continues to develop through its interaction with digital technologies. Such changes in guitar technology are usually grounded in what we might call the "cultural identity" of the instrument: that is, the various ways that the guitar is used to enact, influence and challenge sociocultural and musical discourses. Often, these different uses of the guitar can be seen to reflect a conflict between the changing concepts of "noise" and "musical sound."
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Review(s) of: Settling the Pop Score: Pop Texts and Identity Politics, Stan Hawkins, Aldershot, Hants. : Ashgate, 2002, ISBN 0 7546 0352 0; pb, 234pp, ill, music exx, bibl. , discog. , index. The scholarly study of popular music has its origins in sociology and cultural studies, disciplinary areas in which musical meaning is often attributed to aspects of economical and sociological function. Against this tradition, recent writers have offered what is now referred to as ‘popular musicology’: a method or approach that tends towards a specific engagement with ‘pop texts’ on aesthetic, and perhaps even ‘musical’ terms. Stan Hawkins uses the term popular musicology ‘at his own peril,’ clearly recognising the implicit scholarly danger in his approach, whereby ‘formalist questions of musical analysis’ are dealt with ‘alongside the more intertextual discursive theorisations of musical expression’ (p. xii). In other words, popular musicologists dare to tread that fine line between text and context. As editor of the journal Popular Musicology Online, Hawkins is a leading advocate of this practice, specifically in the application of music-analytical techniques to popular music. His methodology attests to the influence of other leading figures in the area, notably Richard Middleton, Allan F. Moore and Derek Scott (general editor of the Ashgate Popular and Folk Music Series in which this book is published).
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Objective To understand how the formal curriculum experience of an Australian undergraduate pharmacy program supports students’ professional identity formation. Methods A qualitative ethnographic study was conducted over four weeks using participant observation and examined the ‘typical’ student experience from the perspective of a pharmacist. A one-week period of observation was undertaken with each of the four year groups (that is, for years one to four) comprising the undergraduate curriculum. Data were collected through observation of the formal curriculum experience using field notes, a reflective journal and informal interviews with 38 pharmacy students. Data were analyzed thematically using an a priori analytical framework. Results Our findings showed that the observed curriculum was a conventional curricular experience which focused on the provision of technical knowledge and provided some opportunities for practical engagement. There were some opportunities for students to imagine themselves as pharmacists, for example, when the lecture content related to practice or teaching staff described their approach to practice problems. However, there were limited opportunities for students to observe pharmacist role models, experiment with being a pharmacist or evaluate their professional identities. While curricular learning activities were available for students to develop as pharmacists e.g. patient counseling, there was no contact with patients and pharmacist academic staff tended to role model as educators with little evidence of their pharmacist selves. Conclusion These findings suggest that the current conventional approach to the curriculum design may not be fully enabling learning experiences which support students in successfully negotiating their professional identities. Instead it appeared to reinforce their identities as students with a naïve understanding of professional practice, making their future transition to professional practice challenging.
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The notion of identity-based IB cryptography was proposed by Shamir [177] as a specialization of public key PK cryptography which dispensed with the need for cumbersome directories, certificates, and revocation lists.
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Enterprises, both public and private, have rapidly commenced using the benefits of enterprise resource planning (ERP) combined with business analytics and “open data sets” which are often outside the control of the enterprise to gain further efficiencies, build new service operations and increase business activity. In many cases, these business activities are based around relevant software systems hosted in a “cloud computing” environment. “Garbage in, garbage out”, or “GIGO”, is a term long used to describe problems in unqualified dependency on information systems, dating from the 1960s. However, a more pertinent variation arose sometime later, namely “garbage in, gospel out” signifying that with large scale information systems, such as ERP and usage of open datasets in a cloud environment, the ability to verify the authenticity of those data sets used may be almost impossible, resulting in dependence upon questionable results. Illicit data set “impersonation” becomes a reality. At the same time the ability to audit such results may be an important requirement, particularly in the public sector. This paper discusses the need for enhancement of identity, reliability, authenticity and audit services, including naming and addressing services, in this emerging environment and analyses some current technologies that are offered and which may be appropriate. However, severe limitations to addressing these requirements have been identified and the paper proposes further research work in the area.
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An accumulator based on bilinear pairings was proposed at CT-RSA'05. Here, it is first demonstrated that the security model proposed by Lan Nguyen does lead to a cryptographic accumulator that is not collision resistant. Secondly, it is shown that collision-resistance can be provided by updating the adversary model appropriately. Finally, an improvement on Nguyen's identity escrow scheme, with membership revocation based on the accumulator, by removing the trusted third party is proposed.
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Studies of place construction in the rural studies literature have largely privileged the role of professionals over that of local lay actors. This paper contributes to redressing this imbalance through a critical case-study of lay postcard production in a rural shire. Drawing on original, qualitative research conducted in the Shire of Ravensthorpe, Western Australia, including in-depth interviews with key participants, the analysis focuses on this lay production—undertaken in the main by women—as cultural work. By emphasising the work of making the postcards along with the cultural work these postcards achieve, this examination foregrounds intersections of material and imagined ruralities. In the process, this study highlights the complexity and importance of this lay contribution to place identity, particularly as positioned within what may be considered rural cultural work.