ABAKA : a novel attribute-based k-anonymous collaborative solution for LBSs

The increasing use of mobile devices, along with advances in telecommunication systems, increased the popularity of Location-Based Services (LBSs). In LBSs, users share their exact location with a potentially untrusted Location-Based Service Provider (LBSP). In such a scenario, user privacy becomes a major con- cern: the knowledge about user location may lead to her identification as well as a continuous tracing of her position. Researchers proposed several approaches to preserve users’ location privacy. They also showed that hiding the location of an LBS user is not enough to guarantee her privacy, i.e., user’s pro- file attributes or background knowledge of an attacker may reveal the user’s identity. In this paper we propose ABAKA, a novel collaborative approach that provides identity privacy for LBS users considering users’ profile attributes. In particular, our solution guarantees p -sensitive k -anonymity for the user that sends an LBS request to the LBSP. ABAKA computes a cloaked area by collaborative multi-hop forwarding of the LBS query, and using Ciphertext-Policy Attribute-Based Encryption (CP-ABE). We ran a thorough set of experiments to evaluate our solution: the results confirm the feasibility and efficiency of our proposal

Privacy Preserving Multi-Server k-means Computation over Horizontally Partitioned Data

The k-means clustering is one of the most popular clustering algorithms in data mining. Recently a lot of research has been concentrated on the algorithm when the dataset is divided into multiple parties or when the dataset is too large to be handled by the data owner. In the latter case, usually some servers are hired to perform the task of clustering. The dataset is divided by the data owner among the servers who together perform the k-means and return the cluster labels to the owner. The major challenge in this method is to prevent the servers from gaining substantial information about the actual data of the owner. Several algorithms have been designed in the past that provide cryptographic solutions to perform privacy preserving k-means. We provide a new method to perform k-means over a large set using multiple servers. Our technique avoids heavy cryptographic computations and instead we use a simple randomization technique to preserve the privacy of the data. The k-means computed has exactly the same efficiency and accuracy as the k-means computed over the original dataset without any randomization. We argue that our algorithm is secure against honest but curious and passive adversary.Comment: 19 pages, 4 tables. International Conference on Information Systems Security. Springer, Cham, 201

Data sharing in DHT based P2P systems

International audienceThe evolution of peer-to-peer (P2P) systems triggered the building of large scale distributed applications. The main application domain is data sharing across a very large number of highly autonomous participants. Building such data sharing systems is particularly challenging because of the "extreme" characteristics of P2P infrastructures: massive distribution, high churn rate, no global control, potentially untrusted participants... This article focuses on declarative querying support, query optimization and data privacy on a major class of P2P systems, that based on Distributed Hash Table (P2P DHT). The usual approaches and the algorithms used by classic distributed systems and databases forproviding data privacy and querying services are not well suited to P2P DHT systems. A considerable amount of work was required to adapt them for the new challenges such systems present. This paper describes the most important solutions found. It also identies important future research trends in data management in P2P DHT systems

Privacy Intelligence: A Survey on Image Sharing on Online Social Networks

Image sharing on online social networks (OSNs) has become an indispensable part of daily social activities, but it has also led to an increased risk of privacy invasion. The recent image leaks from popular OSN services and the abuse of personal photos using advanced algorithms (e.g. DeepFake) have prompted the public to rethink individual privacy needs when sharing images on OSNs. However, OSN image sharing itself is relatively complicated, and systems currently in place to manage privacy in practice are labor-intensive yet fail to provide personalized, accurate and flexible privacy protection. As a result, an more intelligent environment for privacy-friendly OSN image sharing is in demand. To fill the gap, we contribute a systematic survey of 'privacy intelligence' solutions that target modern privacy issues related to OSN image sharing. Specifically, we present a high-level analysis framework based on the entire lifecycle of OSN image sharing to address the various privacy issues and solutions facing this interdisciplinary field. The framework is divided into three main stages: local management, online management and social experience. At each stage, we identify typical sharing-related user behaviors, the privacy issues generated by those behaviors, and review representative intelligent solutions. The resulting analysis describes an intelligent privacy-enhancing chain for closed-loop privacy management. We also discuss the challenges and future directions existing at each stage, as well as in publicly available datasets.Comment: 32 pages, 9 figures. Under revie

European Perspectives on the Information Society: Annual Monitoring Synthesis and Emerging Trend Updates

This report is one of the outcomes of the EPIS06 Project ¿ European Perspectives on the Information Society ¿ carried out by the ETEPS (European Techno-Economic Policy Support) network in cooperation with the Joint Research Centre Institute for Prospective Technological Studies (JRC IPTS) with the aim of providing strategic intelligence to policy makers by taking a prospective view on the evolution of ICT. This report combines the Annual Monitoring Synthesis (AMS) Report and five Emerging Trend Updates (ETU). It forms one of the main building blocks of the project, establishing an observatory of trends in technology and business evolutions of ICT. More particularly, the Annual Monitoring Synthesis Report (AMS Report) aims to identify new ICT-related developments likely to have a significant impact on the future of the Information Society, both in terms of growth and jobs for Europe and R&D policy prioritisation. By scanning and monitoring recent major foresight exercises and industrial technology roadmaps, as well as other future-oriented analysis and policy papers, the AMS attempts to detect early signals and possible disruptive forces so as to enable timely policy responses and anticipate potential challenges for policy makers. The AMS is structured along six main themes which emerged as a result of the analysis: - Convergence of infrastructures, - Human-computer convergence ¿ technologies for direct human computer interaction, - Pervasive or ubiquitous computing and ambient intelligence, - The future of the Internet, - Citizens¿ concerns, - Working life. A structured overview with a summary of each of the foresights, roadmaps and other sources studied is presented in the AMS report annex. In addition, five Emerging Trends Updates (ETU) present the results of focused briefs on emerging themes of interest for policy making, covering the following topics: - ETU1 on the state-of-the-art of the creative content sector, - ETU2 on ICT and the offshoring of services, - ETU3 on ICT and the role of ICTs as enablers for energy efficiency, - ETU4 on ICT tools and services in intelligent domestic and personal environments, - ETU5 on ICT and privacy in the Knowledge Society ¿ the case of search engines.JRC.J.4-Information Societ

Process Mining Workshops

This open access book constitutes revised selected papers from the International Workshops held at the Third International Conference on Process Mining, ICPM 2021, which took place in Eindhoven, The Netherlands, during October 31–November 4, 2021. The conference focuses on the area of process mining research and practice, including theory, algorithmic challenges, and applications. The co-located workshops provided a forum for novel research ideas. The 28 papers included in this volume were carefully reviewed and selected from 65 submissions. They stem from the following workshops: 2nd International Workshop on Event Data and Behavioral Analytics (EDBA) 2nd International Workshop on Leveraging Machine Learning in Process Mining (ML4PM) 2nd International Workshop on Streaming Analytics for Process Mining (SA4PM) 6th International Workshop on Process Querying, Manipulation, and Intelligence (PQMI) 4th International Workshop on Process-Oriented Data Science for Healthcare (PODS4H) 2nd International Workshop on Trust, Privacy, and Security in Process Analytics (TPSA) One survey paper on the results of the XES 2.0 Workshop is included

Process Mining Workshops

This open access book constitutes revised selected papers from the International Workshops held at the Third International Conference on Process Mining, ICPM 2021, which took place in Eindhoven, The Netherlands, during October 31–November 4, 2021. The conference focuses on the area of process mining research and practice, including theory, algorithmic challenges, and applications. The co-located workshops provided a forum for novel research ideas. The 28 papers included in this volume were carefully reviewed and selected from 65 submissions. They stem from the following workshops: 2nd International Workshop on Event Data and Behavioral Analytics (EDBA) 2nd International Workshop on Leveraging Machine Learning in Process Mining (ML4PM) 2nd International Workshop on Streaming Analytics for Process Mining (SA4PM) 6th International Workshop on Process Querying, Manipulation, and Intelligence (PQMI) 4th International Workshop on Process-Oriented Data Science for Healthcare (PODS4H) 2nd International Workshop on Trust, Privacy, and Security in Process Analytics (TPSA) One survey paper on the results of the XES 2.0 Workshop is included

Towards internet voting in the state of Qatar

Qatar is a small country in the Middle East which has used its oil wealth to invest in the country's infrastructure and education. The technology for Internet voting now exists or can be developed, but are the people of Qatar willing to take part in Internet voting for national elections?. This research identifies the willingness of government and citizens to introduce and participate in Internet voting (I-voting) in Qatar and the barriers that may be encountered when doing so. A secure I voting model for the Qatar government is then proposed that address issues of I-voting which might arise due to the introduction of such new technology. Recommendations are made for the Qatar government to assist in the introduction of I-voting. The research identifies the feasibility of I-voting and the government s readiness and willingness to introduce it. Multiple factors are examined: the voting experience, educational development, telecommunication development, the large number of Internet users, Qatar law which does not bar the use of I-voting and Qatar culture which supports I-voting introduction. It is shown that there is a willingness amongst both the people and the government to introduce I-voting, and there is appropriate accessibility, availability of IT infrastructure, availability of Internet law to protect online consumers and the existence of the e government project. However, many Qataris have concerns of security, privacy, usability, transparency and other issues that would need to be addressed before any voting system could be considered to be a quality system in the eyes of the voters. Also, the need to consider the security threat associated on client-side machines is identified where a lack of user awareness on information security is an important factor. The proposed model attempts to satisfy voting principles, introducing a secure platform for I-voting using best practices and solutions such as the smart card, Public Key Infrastructure (PKI) and digital certificates. The model was reviewed by a number of experts on Information Technology, and the Qatari culture and law who found that the system would, generally, satisfy voting principles, but pointed out the need to consider the scalability of the model, the possible cyber-attacks and the risks associated with voters computers. which could be reduced by enhancing user awareness on security and using secure operating systems or Internet browsers. From these findings, a set of recommendations were proposed to encourage the government to introduce I-voting which consider different aspects of I-voting, including the digital divide, e-literacy, I voting infrastructure, legal aspects, transparency, security and privacy. These recommendations were also reviewed by experts who found them to be both valuable and effective. Since literature on Internet voting in Qatar is sparse, empirical and non-empirical studies were carried out in a variety of surveys, interviews and experiments. The research successfully achieved its aim and objectives and is now being considered by the Qatari Government

Reconceptualising public spaces of (IN)equality: sensing and creating layers of visibility

Tese apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em Geografia e Planeamento Territorial - Especialidade: Geografia HumanaSpace and social identities mutual relation of constitution and reproduction lead us to the understanding that space reflects power relations and hegemonic discourses, and that inequality can perpetuate itself through the ways space is organized, experienced, represented and created. Public spaces are constructed around particular notions of appropriate sexual comportment, reflecting and reproducing heteronormativity, as they exclude non-normative sexualities, such as lesbian sexualities. In a context of a heteronormative socio-spatial landscape women can decide not to disclose their non-normative sexual orientation, leading to a pervasive invisibility of lesbian sexualities in public spaces. Concurrently the pervasive invisibility of lesbian sexualities in public spaces reinforces power inequalities, feeding back the heteronormative socio-spatial landscape. Discrimination on grounds of sexual orientation is still a widespread reality in Portugal in spite of the significant legal advances towards equality in recent years. Discriminated minority groups, such as lesbians, experience power inequalities in their everyday lives, and their spatial invisibility in public spaces contributes to their disempowerment. Communication technologies recast the organization and production of the spatial and temporal scenes of social life and they open new possibilities of public action. The production of alternative representations of space, based on individuals’ georeferenced experiences, thoughts and emotions are increasingly supported by the potentialities of Internet based technologies, such as the ever more easy-to-use online software. The potential of these technologies to promote the agency, to change power relations and to disrupt the hegemonic discourse increase as more people become the authors of a complementary flow of knowledge, information, memories and stories. This research explores the potential of geospatial online practices, based upon the experiences, emotions and feelings of lesbian and bisexual women to disclose the socially encoded meanings of different bodies in specific spatial, temporal and cultural contexts, highlighting how spaces and sexual identities are mutually constitutive. This research project aims to explore the potential of collaborative web mapping to promote the agency and empowerment of lesbian and bisexual women. It is structured in three phases: ‘Mapping the landscape’ aims to map spaces of lesbian and gay visibility in public spaces to contextualise the hetero pervasive reality in Portugal; the second phase ‘Sensing the landscape’ focuses on the intersections of gender and sexual orientation, aiming to identify significant dimensions of space and places that relate to lesbian and bisexual women sexual identities; and the third and final phase of the research ‘Creating landscapes’ explores how creating and sharing digital layers of lesbian visibility on collaborative web maps can disrupt a hetero pervasive reality and impact social identity and belonging, building capacities for action of lesbian and bisexual women, and facilitating same-sex public displays of affection. Ultimately, this research aims to explore the empowering potentialities of geospatial online practices to provide alternative possibilities for citizenship, and foster social change

Protecting Data Privacy in Structured P2P Networks

International audienceP2P systems are increasingly used for efficient, scalable data sharing. Popular applications focus on massive file sharing. However, advanced applications such as online communities (e.g., medical or research communities) need to share private or sensitive data. Currently, in P2P systems, untrusted peers can easily violate data privacy by using data for malicious purposes (e.g., fraudulence, profiling). To prevent such behavior, the well accepted Hippocratic database principle states that data owners should specify the purpose for which their data will be collected. In this paper, we apply such principles as well as reputation techniques to support purpose and trust in structured P2P systems. Hippocratic databases enforce purpose-based privacy while reputation techniques guarantee trust. We propose a P2P data privacy model which combines the Hippocratic principles and the trust notions. We also present the algorithms of PriServ, a DHT-based P2P privacy service which supports this model and prevents data privacy violation. We show, in a performance evaluation, that PriServ introduces a small overhead