Elisa Bertino, Elena Ferrari, Andrea Perego

World Wide Web, 13(3):215–249, 2010.

Web content filtering is a means to make end-users aware of the ‘quality’ of Web resources by evaluating their contents and/or characteristics against users' preferences. Although they can be used for a variety of purposes, Web content filtering tools are mainly deployed as a service for parental control purposes, and for regulating the access to Web content by users connected to the networks of enterprises, libraries, schools, etc. Current Web filtering tools are based on well established techniques, such as data mining and firewall blocking, and they typically cater to the filtering requirements of very specific end-user categories. Therefore, what is lacking is a unified filtering framework able to support all the possible application domains, and making it possible to enforce interoperability among the different filtering approaches and the systems based on them. In this paper, a multi-strategy approach is described, which integrates the available techniques and focuses on the use of metadata for rating and filtering Web information. Such an approach consists of a filtering meta-model, referred to as MFM (Multi-strategy Filtering Model), which provides a general representation of the Web content filtering domain, independently from its possible applications, and of two prototype implementations, partially carried out in the framework of the EU projects EUFORBIA and QUATRO, and designed for different application domains: user protection and Web quality assurance, respectively.

DOI: 10.1007/s11280-009-0073-5

Categories: Web Rating & Filtering

Andrea Perego, Barbara Carminati, Elena Ferrari

Proceedings: International Workshop on Collaborative Social Networks (CollaborateSN 2009), pp. 1–8, 2009

In this paper, we present a collaborative social networking environment, referred to as Quality Social Network (QSN), which enhances the social tagging paradigm by using it as a basis to evaluate the quality of Web resources, on the basis of the user preferences specified by each QSN member. Such features give end users the ability of being aware of the “quality” of the resources they are accessing, based on the opinions of the members of their community, and of being informed whether such resources can be safely used, according to the requirements specified by end users themselves. Besides illustrating the main characteristics of the QSN and its architecture, we describe its prototype implementation, carried out in the framework of the QUATRO Plus EU project, and its application to a use case scenario, involving groups of teenagers from three different European countries, acting as Youth Panels of the Safer Internet EU Programme.

DOI: 10.4108/ICST.COLLABORATECOM2009.8368

Categories: Social Networks, Semantic Web, Web Rating & Filtering

Barbara Carminati, Elena Ferrari, Andrea Perego

ACM Transactions on Information & System Security, 13(1):6, 2009.

In this paper, we propose an access control mechanism for Web-based Social Networks, which adopts a rule-based approach for specifying access policies on the resources owned by network participants, and where authorized users are denoted in terms of the type, depth, and trust level of the relationships existing between nodes in the network. Differently from traditional access control systems, our mechanism makes use of a semi-decentralized architecture, where access control enforcement is carried out client-side. Access to a resource is granted when the requestor is able to demonstrate of being authorized to do that, by providing a proof. In the paper, besides illustrating the main notions on which our access control model relies, we present all the protocols underlying our system and a performance study of the implemented prototype.

DOI: 10.1145/1609956.1609962

Categories: Access Control, Social Networks

Phil Archer, Kevin Smith, Andrea Perego

W3C Recommendation, Sep. 2009.

The purpose of the Protocol for Web Description Resources (POWDER) is to provide a means for individuals or organizations to describe a group of resources through the publication of machine-readable metadata, as motivated by the POWDER Use Cases. This document details the creation and lifecycle of Description Resources (DRs), which encapsulate such metadata. These are typically represented in a highly constrained XML dialect that is relatively human-readable. The meaning of such DRs are underpinned by formal semantics, accessible by performing a GRDDL Transform.

Categories: Semantic Web

Phil Archer, Andrea Perego, Kevin Smith

W3C Recommendation, Sep. 2009.

The Protocol for Web Description Resources (POWDER) facilitates the publication of descriptions of multiple resources such as all those available from a Web site. This document describes how sets of IRIs can be defined such that descriptions or other data can be applied to the resources obtained by dereferencing IRIs that are elements of the set. IRI sets are defined as XML elements with relatively loose operational semantics. This is underpinned by the formal semantics of POWDER which include a semantic extension, defined separately. A GRDDL transform is associated with the POWDER namespace that maps the operational to the formal semantics.

Categories: Semantic Web

Phil Archer, Elena Ferrari, Vangelis Karkaletsis, Stasinos Konstantopoulos, Antonis Koukourikos, Andrea Perego

Proceedings: Workshop on Trust and Privacy on the Social and Semantic Web (SPOT 2009), 2009

The QUATRO Plus project, a follow on from the original QUATRO Project, aims to balance the wisdom of the crowds with the knowledge of the experts. It uses a mixture of authenticated data sources and the opinions of end users expressed through social networking software to build a dataset that is authoritative and trustworthy. The dataset describes online resources using RDF with the upcoming W3C Recommendation, POWDER, as the underlying transport and storage mechanism. Data can be added to or queried through a variety of tools provided by the project, some of which are described in detail in this paper.

Categories: Social Networks, Semantic Web, Web Rating & Filtering

Barbara Carminati, Elena Ferrari, Andrea Perego

Proceedings: International Conference on Collaborative Computing (CollaborateCom 2008), pp. 126–144, 2008

The original purpose of Web metadata was to protect end-users from possible harmful content and to simplify search and retrieval. However they can also be exploited in more enhanced applications, such as Web access personalization on the basis of end-users' preferences. In order to achieve this, it is however necessary to address several issues. One of the most relevant is how to assess the trustworthiness of Web metadata. In this paper, we discuss how such issue can be addressed through the use of collaborative and Semantic Web technologies. The system we propose is based on a Web-based Social Network, where members are able not only to specify labels, but also to rate existing labels. Both labels and ratings are then used to assess the trustworthiness of resources' descriptions and to enforce Web access personalization.

DOI: 10.1007/978-3-642-03354-4_11

Categories: Social Networks, Semantic Web, Web Rating & Filtering

Barbara Carminati, Elena Ferrari, Andrea Perego

International Journal of Information Security and Privacy, 2(4):22–53, 2008.

The wide diffusion and usage of social networking Web sites in the last years have made publicly available a huge amount of possible sensitive information, which can be used by third-parties with purposes different from the ones of the owners of such information. Currently, this issue has been addressed by enforcing into Web-based Social Networks (WBSNs) very simple protection mechanisms, or by using anonymization techniques, thanks to which it is possible to hide the identity of WBSN members while performing analysis on social network data. However, we believe that further solutions are needed, to allow WBSN members themselves to decide who can access their personal information and resources. To cope with this issue, in this article we illustrate a decentralized security framework for WBSNs, which provide both access control and privacy protection mechanisms. In our system, WBSN members can denote who is authorized to access the resources they publish and the relationships they participate in, in terms of the type, depth, and trust level of the relationships existing between members of a WBSN. Cryptographic techniques are then used to provide a controlled sharing of resources while preserving relationship privacy.

DOI: 10.4018/jisp.2008100102

Categories: Security, Privacy, Social Networks

Barbara Carminati, Elena Ferrari, Andrea Perego

In: Encyclopedia of Information Science and Technology, 2nd Edition. IGI Publishing, vol. VII, Chap. 535, pp. 3369–3376, 2008.

DOI: 10.4018/978-1-60566-026-4.ch535

Categories: Security, Privacy, Social Networks

Horst Eidenberger, Susanne Boll, Stavros Christodoulakis, Doris Divotkey, Klaus Leopold, Alessandro Martin, Andrea Perego, Ansgar Scherp, Chrisa Tsinaraki

Proceedings: DELOS Conference (DELOS 2007), pp. 87–103, 2007

In this paper we present CoCoMA, an integrated platform, developed in the framework of the DELOS II European Network of Excellence on Digital Libraries, aiming at the unification of the most important aspects of multimedia management and multimedia presentation. The paramount goal of CoCoMA is to maximize the added value from task and data integration by the identification and exploitation of connection points and inherent workflow similarities. The paper provides a brief description of the involved research fields, suggests an architecture for integrated multimedia consumption and presentation, and discusses the most prominent connection points. Problems and solutions are discussed jointly, and illustrated by the components of the application prototype developed for the DELOS project.

DOI: 10.1007/978-3-540-77088-6_9

Categories: Multimedia, Digital Libraries

Elisa Bertino, Elena Ferrari, Andrea Perego, Gian Piero Zarri

In: Encyclopedia of Internet Technologies and Applications. IGI Publishing, Chap. 6, pp. 36–44, 2007.

DOI: 10.4018/978-1-59140-993-9.ch006

Categories: Web Rating & Filtering

Barbara Carminati, Elena Ferrari, Andrea Perego

Proceedings: ICDE Workshops 2007, pp. 163–171, 2007

Current social networks implement very simple protection mechanisms, according to which a user can state whether his/her personal data, relationships, and resources should be either public or accessible only by him/herself (or, at most, by users with whom he/she has a direct relationship). This is not enough, in that there is the need of more flexible mechanisms, making a user able to decide which network participants are authorized to access his/her resources and personal information. With this aim, in a previous paper we have proposed an access control model where authorized users are denoted based on the relationships they participate in. Nonetheless, we believe that this is just a first step towards a more comprehensive privacy framework for social networks. Indeed, besides users' resources and personal data, also users' relationships may convey sensitive information. For this reason, in this paper we focus on relationship protection, by proposing a strategy exploiting cryptographic techniques to enforce a selective dissemination of information concerning relationships across a social network.

DOI: 10.1109/ICDEW.2007.4400987

Categories: Privacy, Social Networks

Chrisa Tsinaraki, Andrea Perego, Panagiotis Polydoros, Athina Syntzanaki, Alessandro Martin, Stavros Christodoulakis

Journal of Digital Information Management, 4(4):207–213, 2006.

We present in this paper an integrated system that allows the management and annotation of multimedia objects stored in MPEG-7/21 repositories, and the specification and semi-automatic generation of multimedia presentations based on the content relationships that exist between the multimedia objects. This system is the outcome of the collaboration between the Technical University of Crete (TUC-MUSIC) and the University of Milan (UNIMI) in the CoCoMA project of the DELOS II European Network of Excellence on Digital Libraries. The resulting system is one of the main components of the CoCoMA infrastructure that aims to provide content- and context-aware rich interactive multimedia presentations by controlling data fusion and metadata reuse. The integrated system utilizes the SyMPA management and presentation authoring system developed by UNIMI and the DS-MIRF framework developed by TUC-MUSIC.

Categories: Multimedia Presentations, Digital Libraries

Barbara Carminati, Elena Ferrari, Andrea Perego

Proceedings: OTM Workshops 2006, pp. 1734–1744, 2006

Web-based social networks (WBSNs) are online communities where participants can establish relationships and share resources across the Web with other users. In recent years, several WBSNs have been adopting Semantic Web technologies, such as FOAF, for representing users' data and relationships, making it possible to enforce information interchange across multiple WBSNs. Despite its advantages in terms of information diffusion, this raised the need of giving content owners more control on the distribution of their resources, which may be accessed by a community far wider than they expected. In this paper, we present an access control model for WBSNs, where policies are expressed as constraints on the type, depth, and trust level of existing relationships. Relevant features of our model are the use of certificates for granting relationships' authenticity, and the client-side enforcement of access control according to a rule-based approach, where a subject requesting to access an object must demonstrate that it has the rights of doing that.

DOI: 10.1007/11915072_80

Categories: Access Control, Social Networks

Vangelis Karkaletsis, Andrea Perego, Phil Archer, Kostas Stamatakis, Pantelis Nasikas, David Rose

Proceedings: WWW Workshops 2006, 2006

QUATRO is an on-going EC-funded project which aims to provide a common vocabulary and machine readable schema for quality labeling of Web content, as well as ways to automatically show the contents of the label(s) found in a Web resource, and functionalities for checking the validity of these labels. The paper presents the QUATRO processes for label validation and user notification, and outlines the architecture of QUATRO system.

Categories: Web Rating & Filtering

Elisa Bertino, Elena Ferrari, Andrea Perego

In: Web and Information Security. IDEA Group, Chap. 6, pp. 113–133, 2005.

The need to filter online information in order to protect users from possible harmful content can be considered as one of the most compelling social issues derived from the transformation of the Web into a public information space. Despite that Web rating and filtering systems have been developed and made publicly available quite early, no effective approach has been established so far, due to the inadequacy of the proposed solutions. Web filtering is then a challenging research area, needing the definition and enforcement of new strategies, considering both the current limitations and the future developments of Web technologies—in particular, the upcoming Semantic Web. In this chapter, we provide an overview of how Web filtering issues have been addressed by the available systems, bringing in relief both their advantages and shortcomings, and outlining future trends. As an example of how a more accurate and flexible filtering can be enforced, we devote the second part of this chapter to describing a multi-strategy approach, of which the main characteristics are the integration of both list- and metadata-based techniques and the adoption of sophisticated metadata schemes (e.g., conceptual hierarchies and ontologies) for describing both users' characteristics and Web pages content.

DOI: 10.4018/978-1-59140-588-7.ch006

Categories: Web Rating & Filtering

Elisa Bertino, Elena Ferrari, Andrea Perego, Gian Piero Zarri

Proceedings: DEXA Workshops 2005, pp. 519–523, 2005

This paper illustrates some of the Semantic Web techniques used in the framework of the EU project EUFORBIA, which deals with the rating and filtering of ‘questionable’ Web sites concerned with racism, violence, pornography, etc. The rationale for using a high-level semantic approach in this domain is linked with the assumption that an in-depth description of the ‘semantic content’ of Web sites should allow the implementation of filtering strategies more flexible, accurate and (neatly) sophisticated than the current ones. From a technical point of view, the final result of the project consists of two integrated prototypes that communicate through a common ontology.

DOI: 10.1109/DEXA.2005.21

Categories: Web Rating & Filtering

Elisa Bertino, Elena Ferrari, Andrea Perego, Diego Santi

Proceedings: IEEE International Conference on Multimedia & Expo (ICME 2005), pp. 578–581, 2005

Synchronized multimedia applications play an important role in a Digital Library environment, since they allow one to efficiently disseminate knowledge among differently skilled users through an approach which is more direct than the classic ‘static’ documents. In this paper, we propose a new authoring approach based on an innovative presentation structure and a new class of contentbased constraints. Thanks to a flexible heuristic process, such features allow the author to easily combine several multimedia objects into a multi-topic presentation, whose different contents can be freely chosen by end users according to their preferences or skills.

DOI: 10.1109/ICME.2005.1521489

Categories: Multimedia Presentations, Digital Libraries

Wolfgang Lindner, Andrea Perego (Eds.)

Categories: Varia

Elisa Bertino, Elena Ferrari, Andrea Perego

International Journal of Information Security, 2(1):45–58, 2003.

Internet filtering has particular requirements which traditional access control approaches cannot satisfy. In this paper, we present a multi-strategy filtering model tailored specifically to both digital library and Web environments whose key features are the support for credential and content-based filtering and its full integration with standard Internet rating systems. Moreover, we describe the prototype system implementing our model and developed in the framework of the European project EUFORBIA.

DOI: 10.1007/s10207-003-0024-6

Categories: Web Rating & Filtering

Elisa Bertino, Elena Ferrari, Andrea Perego

Proceedings: International Computer Software and Applications Conference (COMPSAC 2002), pp. 945–950, 2002

Digital Libraries (DLs) introduce several challenging requirements with respect to the formulation, specification and enforcement of adequate access control policies. Unlike conventional database environments, a DL typically is characterised by a dynamic subject population, often making accesses from remote locations, and by an extraordinarily large amount of information, stored in a variety of formats. Additionally, protecting a DL does not only means protecting documents that reside at the DL site, but also protecting accesses that the DL subscribers made to external Web documents. In this paper we present MaΧ, a comprehensive system for enforcing access control, specifically tailored to both DL and Web environments. Key features of MaΧ are the support for credential and content-based access control to DL and Web documents, and its full integration with standard Internet rating systems.

DOI: 10.1109/CMPSAC.2002.1045127

Categories: Access Control, Web Rating & Filtering, Digital Libraries, Web