A new definition of homomorphic signature for identity management in mobile cloud computing

In this paper, we define a new homomorphic signature for identity management in mobile cloud computing. A mobile user firstly computes a full signature on all his sensitive personal information (SPI), and stores it in a trusted third party (TTP). During the valid period of his full signature, if the user wants to call a cloud service, he should authenticate him to the cloud service provider (CSP) through TTP. In our scheme, the mobile user only needs to send a {0,1}ⁿ${\{0,1\}}^n$ vector to the access controlling server (TTP). The access controlling server who doesn?t know the secret key can compute a partial signature on a small part of user?s SPI, and then sends it to the CSP. We give a formal secure definition of this homomorphic signature, and construct a scheme from GHR signature. We prove that our scheme is secure under GHR signature.     

To boldly go where no group has gone before: An analysis of online group identity and validation of a measure

Online groups have become more popular in recent decades, in both research and practice. Many authors have proposed important outcomes of group membership, and some have even investigated some preliminary dynamics of these online groups. Unfortunately, no validated measure of online group identity exists, causing these researchers to employ measures with poor psychometric properties or concerning construct validity. For these reasons, the current article undergoes a multiple study process to validate a measure of online group identity. In doing so, several aspects of online group identity are discovered, largely based on propositions previously posed for offline groups. Study 1 demonstrates that individuals from a general sample identify with online groups, and the measure has an identifiable factor structure. Using a naturally occurring online group, Study 2 shows the measure’s concurrent, convergent, and divergent validity, while simultaneously revealing many novel relationships of online group identity. Lastly, Study 3 investigates the effect of The United States President, Barack Obama, creating an account on the website studied in Study 2 and interacting with group members. The results of Study 3 reveal that online group identity did not change after this historic event, although members had notable emotional responses. In all, the current study illustrates the validity of an online group identity measure, and discovers many important relationships previously unknown in regards to online group identity. It is believed that the investigated measure of online group identity will become an important tool in future research, especially when further probing the relationships analyzed in the current study. Further implications and suggestions for future studies are discussed.     

A group process for defining local software quality: Field applications and validation experiments

‘Global’ measures of software quality are generally not used by practitioners because they have not been calibrated for local operating environments. A participative process for defining local software quality has been defined, applied in the field, and evaluated in formal validation experiments. In four field applications of the process, a ‘jury’ of seasoned practitioners ranked a sample of modules from the organization's inventory of code and produced a ‘software quality rule set’. The results of each field application were tested in a formal validation experiment to determine whether the obtained rule set was a valid representation of the organization's sense of quality, i.e. whether the locally-derived rules could enable non-organizational programmers to make judgments about quality that were similar to those of the jury. In each experiment, non-organizational programmers ranked the same set of modules that were ranked by the organization's jury, using either the locally-derived rules, generic (textbook) rules, placebo (non-helpful) rules, or no rules. The correlation between the judgments of non-organizational programmers using local rules and the jury was statistically significant at p < 0–005; all other correlations were significant at p < 0–005. The results support a conclusion that the group process for defining local software quality is reliable in producing valid rule sets.     

Linking analytic hierarchy process and social choice methods to support group decision-making in water management

The social choice (SC) theory is in close relation with multicriteria decision-making (MCDM), especially in group decision contexts. SC theory includes various voting systems while MCDM is represented by utility and outranking methods; among utility models, the analytic hierarchy process (AHP) is probably the most popular in group decision support. In this paper, we investigate two possible contexts in modeling decentralized decision problems in water management. The first is based on AHP only and two group aggregation techniques. The second one assumes the AHP application in subgroups, while at a group level, aggregation is performed by the SC voting procedures. Comparative analyses show good agreement of the results when two methodologies are applied as the decision support to the water committee of the San Francisco river basin in Brazil. The second methodology (called AHP + SC) is considered more promising for implementation in real-decision situations in water management.     

The development of group identity in computer and face-to-face groups with membership change

A three-part conception of group identity is proposed that draws on common fate, cohesiveness, and cognitive views of group identity. The changing contribution of these three components to group identity was examined for 31 original and 29 reconfigured groups which met for 7 consecutive weeks using either face-to-face (FIF) or computer-mediated communication (CMC). Group identity was consistently lower for computer-mediated groups, and this effect was stronger in the reconfigured groups. In the original groups, group identity started high and declined for both FTF and CMC groups. In the reconfigured groups, developmental patterns differed from those of the original groups, and also differed by communication medium. Individual differences accounted for a substantial amount of variance in group identity across original and reconfigured groups.     

Group norms,media preferences,and group meeting success: A longitudinal study

Group norms are known to have an effect on group meeting success. But to what extent do these norms affect choice of media for communication of group members, and what role does this effect play, if any, in group meeting success? This paper empirically examines these questions. It takes a novel approach in considering these questions longitudinally to investigate the importance of the formation and affect of norms over time. The study presented here showed that group norms do influence group member media preference and that, over time, these effects grow stronger. Furthermore, a strong positive association between the similarity of group media preferences and group meeting success is revealed. The paper concludes with a discussion of the importance and implications of understanding the effect of group norms on technology use and meeting success.     

计算机系统课程群的构建与实践研究

本文介绍了我院构建计算机系统课程群的具体实施,包括整合课程内容,提出层次化、系列化的课程体系;提出与理论教学密切配合的、适合能力和技能培养的实践教学体系;引入电子学习系统平台作为教学手段的扩充等。实践表明,这是培养具有认知和创新能力的高素质专业人才高素质人才的有效途径。     

Virtually homosexual: Technoromanticism,demarginalisation and identity formation among homosexual males

‘Coming out’ is a key stage in the identity formation process for the homosexual male when the individual discloses his homosexual status to himself and others. Although previous research has indicated that homosexual men often use the Internet and computer-mediated communication (CMC) during the identity formation process to discover and develop their sexual and self-identities, studies to date have focused on their use of text-based CMC with scant attention paid to experiences within virtual worlds. This study explored whether homosexual males use virtual worlds in the sexual identity formation process and, specifically, the applicability of technoromanticism within this context. Qualitative retrospective biographical interviews were undertaken with 12 self-selected individuals who had engaged with virtual worlds before or during their sexual identity development. The CASE model (Community, Anonymity, Sexual experimentation, and Escape) was developed to characterise the key themes emerging from the data and illustrate the enactment of technoromanticism by homosexual males within virtual worlds. It is concluded that technoromanticism in virtual worlds can only have a profound impact on individuals if the individual’s personal development online is transferred offline as there is a potential to become toxically immersed and thus stall or halt the identity development process altogether.     

A video recording and viewing protocol for student group presentations: Assisting self-assessment through a Wiki environment

The purpose of this research was to firstly develop a protocol for video recording student group oral presentations, for later viewing and self-assessment by student group members. Secondly, evaluations of students' experiences of this process were undertaken to determine if this self-assessment method was a positive experience for them in gaining insights into the quality of their group's presentation. Participants were students undertaking a first year course in a bachelor of business degree within an Australian university. Students were surveyed twice, once prior to group formation to determine their previous oral group presentation experiences and then after viewing their presentations. Data from survey items assessing students' perspectives on the utility of viewing their video presentations, within their group Wikis, revealed that watching the video of their group presentation was an effective method of feedback and could improve both group and individual performance in the future. Further, content analysis of open ended survey questions and focus groups identified that students were highly engaged in the activity and after reviewing and reflecting on their video recording had deeper insights and raised awarenesses of making group presentations. Students identified that this experience would benefit any future group oral presentations they made.     

A nexus of Cyber-Geography and Cyber-Psychology: Topos/“Notopia” and identity in hacking

This paper explores the Cyber-Psychological and Cyber-Geographic aspects of hacking and hacktivism. An examination of the literature related to hackers and hacking reveals a complex nexus of spatial (including cyber-spatial such as “Notopia”) and psychological aspects of hacking, from which emerges a central question of how humans perceive and manipulate their cyber-identities. Concealing (real and cyber) identities is typical in hacking. With our progressive acculturation with identity-less and place-less modes of existence, our cyber-identities through time may be studied from within John Locke’s criterion of “memory” and the spatial-geographical criterion of identity.     

Multimedia group and inter-stream synchronization techniques: A comparative study

This paper presents the most comprehensive analysis and comparison of the most-known multimedia group and inter-stream synchronization approaches. Several types of multimedia synchronization are identified but only inter-stream and group synchronization algorithms are considered. This is the first survey including group synchronization techniques. A classification of the main synchronization techniques included in most of the analyzed algorithms complements the paper. Finally, a table is presented summarizing the main characteristics of each analyzed algorithm according to those techniques and other critical issues.     

A view of group decision making process and bivoting approach

Many characteristics of Group Decision Making (GDM) are different from those of individual decision. The literature dealing with the stages of GDM is rather scant. This paper presents a view about the stages of group decision processes, characterizing GDM as a dynamic process. We discuss particularly the aggregation stage of preferences and reports a bivoting approach' used in practising group decision support systems (GDSS). Finally, a concrete example is given to illustrate each stage of group decision process and tile 'bivoting approach' in consensus reaching stage.     

Performance analysis of hierarchical group key management integrated with adaptive intrusion detection in mobile ad hoc networks

We develop a mathematical model to quantitatively analyze a scalable region-based hierarchical group key management protocol integrated with intrusion detection to deal with both outsider and insider security attacks for group communication systems (GCSs) in mobile ad hoc networks (MANETs). Our proposed adaptive intrusion detection technique is based on majority voting by nodes in a geographical region to cope with collusion of compromised nodes, with each node preloaded with anomaly-based or misuse-based intrusion detection techniques to diagnose compromised nodes in the same region. When given a set of parameter values characterizing operational and environmental conditions, we identify the optimal intrusion detection rate and the optimal regional area size under which the mean time to security failure of the system is maximized and/or the total communication cost is minimized for GCSs in MANET environments. The tradeoff analysis in performance versus security is useful in identifying and dynamically applying optimal settings to maximize the system lifetime for scalable mobile group applications while satisfying application-specific performance requirements.     

Determining key capabilities in technology management using fuzzy analytic hierarchy process: A case study of Turkey

The importance of technology management is a vital determinant of long-run success or failure of organizations in today’s world. Since technology is a major driver of the global economic development, business professionals seek more effective ways to manage existing and emerging technology. This study proposes a model to understand the links between competitive advantages, competitive priorities and competencies of a firm in the context of the technology management. We use the fuzzy analytical hierarchy process (AHP) to analyze these links. Moreover, we examine the perception of a group of managers from different Turkish firms regarding the technology management. The main result of this paper is that the concept of the management of technology arises to be much more important than both the product technology and the process technology.     

HCI as heterodoxy: Technologies of identity and the queering of interaction with computers

As digital technologies are woven more closely into identity formation, society needs ways to keep tools flexible to many versions of self-presentation and avoid perpetuating the political status quo through conservative and apolitical designing. This paper explores one route, drawing on Queer Theory to look at resistance to computer formalisation of identity through queering. Several case studies explore how we might apply the oblique route to design of a range of technologies that help users define themselves. In particular, forgetting, obscuring, cheating and eluding are activities held up to counter computer strengths and offer a more flexible vision of interaction design for the future.     

Analyzing settings for social identity management on Social Networking Sites: Classification,current state,and proposed developments

The rising prevalence of Social Networking Sites (SNS) and their usage in multiple contexts poses new privacy challenges and increasingly prompts users to manage their online identity. To address privacy threats stemming from interacting with other users on SNS, effective Social Identity Management (SIdM) is a key requirement. It refers to the deliberate and targeted disclosure of personal attribute values to a subset of one's contacts or other users on the SNS. Protection against other entities such as the site operator itself or advertisers and application programmers is not covered by SIdM, but could be incorporated in further refinement steps. Features and settings to perform SIdM have been proposed and subsequently implemented partly by some SNS. Yet, these are often isolated solutions that lack integration into a reference framework that states the requirements for successfully managing one's identity. In this article, such a reference framework of existing and desired SIdM settings is derived from identity theory, literature analysis, and existing SNS. Based thereupon, we examine the SIdM capabilities of prevalent SNS and highlight possible improvements. Lastly, we reason about developing a metric to objectively compare the capability of SNS in regards to their support for SIdM.     

Effects of group arguments on rumor belief and transmission in online communities: An information cascade and group polarization perspective

The proliferation of the Internet and online communities has greatly increased the number and transmission speed of online rumors. To take more effective measures to counter the negative effects of these rumors, researchers and companies should understand the underlying mechanism of online rumor transmission. Therefore, this study takes an early initiative by focusing on users’ arguments in online discussion forums on the rumors and their effects on an individual’s belief in rumor and belief change, which is guided by the informational cascade and group polarization theories. In turn, belief and belief change on the online rumor lead to intention to spread the rumor. A lab experiment was conducted to test research hypotheses. The results, implications, limitations of the study, and conclusion are presented.     

Multimedia security in group communications: recent progress in key management,authentication, and watermarking

Multicast is an internetwork service that provides efficient delivery of data from a source to multiple receivers. It reduces the bandwidth requirements of the network and the computational overhead of the host devices. This makes multicast an ideal technology for communication among a large group of participants. Secure group communications involves many service types include teleconferencing, pay TV and real-time delivery of stock quotes. IP multicast is the traditional mechanism to support multicast communications. Multicast security includes group membership control, secure key distribution, secure data transfer and copyright protection. This paper is an overview of the schemes proposed for group key management, authentication and watermarking in wired networks with fixed members and wireless networks with mobile members.A preliminary version of this paper was presented at the IASTED International Conference on Communications and Computer Networks, Cambridge, MA 4-6 November 2002.     

A scalable key management and clustering scheme for wireless ad hoc and sensor networks

This paper describes a scalable key management and clustering scheme for secure group communications in ad hoc and sensor networks. The scalability problem is solved by partitioning the communicating devices into subgroups, with a leader in each subgroup, and further organizing the subgroups into hierarchies. Each level of the hierarchy is called a tier or layer. Key generation, distribution, and actual data transmissions follow the hierarchy. The distributed, efficient clustering approach (DECA) provides robust clustering to form subgroups, and analytical and simulation results demonstrate that DECA is energy-efficient and resilient against node mobility. Comparing with most other schemes, our approach is extremely scalable and efficient, provides more security guarantees, and is selective, adaptive and robust.