0000000001325975
AUTHOR
Laura Ricci
showing 21 related works from this author
Logical Key Hierarchy for Group Management in Distributed Online Social Networks
2016
Distributed Online Social Networks (DOSNs) have recently been proposed to shift the control over user data from a unique entity to the users of the DOSN themselves. In this paper, we focus our attention on the problem of privacy preserving content sharing to a large group of users of the DOSNs. Several solutions, based on cryptographic techniques, have been recently proposed. The main challenge here is the definition of a scalable and decentralized approach that: i) minimizes the re-encryption of the contents published in a group when the composition of the group changes and ii) enables a fast distribution of the cryptographic keys to all the members (n) of a group, each time a new user is …
Epidemic diffusion of social updates in Dunbar-based DOSN
2014
Distributed Online Social Networks (DOSNs) do not rely on a central repository for storing social data so that the users can keep control of their private data and do not depend on the social network provider. The ego network, i.e. the network made up of an individual, the ego, along with all the social ties she has with other people, the alters, may be exploited to define distributed social overlays and dissemination protocols. In this paper we propose a new epidemic protocol able to spread social updates in Dunbar-based DOSN overlays where the links between nodes are defined by considering the social interactions between users. Our approach is based on the notion of Weighted Ego Betweenne…
A Conceptual Model for Blockchain-Based Agriculture Food Supply Chain System
2022
In agriculture supply chain management, traceability is a crucial aspect to ensure food safety for increasing customer loyalty and satisfaction. Lack of quality assurance in centralized data storage makes us move towards a new approach based on a decentralized system in which transparency and quality assurance is guaranteed throughout the supply chain from producer to consumer. The current supply chain model has some disadvantages like a communication gap between the entities of the supply chain and no information about the travel history and origin of the product. The use of technology improves the communication and relation between various farmers and stakeholders. Blockchain technology a…
Distributed Coverage of Ego Networks in F2F Online Social Networks
2016
Although most online social networks rely on a centralized infrastructure, several proposals of Distributed Online Social Networks (DOSNs) have been recently presented. Since in DOSNs user profiles are stored on the peers of the users belonging to the network, one of the main challenges comes from guaranteeing the profile availability when the owner of the data is not online. In this paper, we propose a DOSN based on a friend-to-friend P2P overlay where the user's data is stored only on friend peers. Our approach is based on the ego-network concept, which models the social network from the local point of view of a single user. We propose a distributed algorithm which is based on the notion …
A Logical Key Hierarchy Based approach to preserve content privacy in Decentralized Online Social Networks
2020
Distributed Online Social Networks (DOSNs) have been proposed to shift the control over user data from a unique entity, the online social network provider, to the users of the DOSN themselves. In this paper we focus on the problem of preserving the privacy of the contents shared to large groups of users. In general, content privacy is enforced by encrypting the content, having only authorized parties being able to decrypt it. When efficiency has to be taken into account, new solutions have to be devised that: i) minimize the re-encryption of the contents published in a group when the composition of the group changes; and, ii) enable a fast distribution of the cryptographic keys to all the m…
An analysis of ego network communities and temporal a affinity for online social networks
2017
The wide diffusion of Online Social Networks (OSNs) presents several advantages, like the definition of simple tools for information sharing and spreading. However, OSNs present also some drawbacks, one of the most important one is the problem of privacy disclosures. Distributed Online Social Networks (DOSNs), which decentralize the control of the social network, have been recently proposed to overcome these issues. The decentralization of the control has issued several challenges, one of the main ones is guaranteeing data availability without relying on a central server. To define users’ data allocation strategies, the knowledge of the structure of the ego network and of the user’ temporal…
Trusted dynamic storage for dunbar-based P2P online social networks
2014
Online Social Networks (OSNs) are becoming more and more popular in today's Internet. Distributed Online Social Networks (DOSNs), are OSNs which do not exploit a central server for storing users' data and enable users to have more control on their profile content, ensuring a higher level of privacy. The main challenge of DOSNs comes from guaranteeing availability of the data when the data owner is offline. In this paper we propose a new P2P dynamic approach to the problem of data persistence in DOSNs. By following Dunbar's approach, our system stores the data of a user only on a restricted number of friends which have regular contacts with him/her. Users in this set are chosen by considerin…
A Smart Contract Based Recommender System
2019
Nowadays information available on the World Wide Web has reached unprecedented growth and it makes difficult for users to find the most relevant for them. In order to alleviate such issue, Recommender Systems (RSs) have been proposed to collect opinions and preferences about a set of items, process such preferences and build a personalized information access. While the most part of current RSs exploit centralized architecture to provide the service, in this manuscript we propose an alternative approach for building a general purpose RSs that provides to users with more transparent and decentralized rating strategy. Indeed, the proposed framework is built on top of a Distributed Ledger techn…
Discovering Homophily in Online Social Networks
2018
During the last ten years, Online Social Networks (OSNs) have increased their popularity by becoming part of the real life of users. Despite their tremendous widespread, OSNs have introduced several privacy issues as a consequence of the nature of the information involved in these services. Indeed, the huge amount of private information produced by users of current OSNs expose the users to a number of risks. The analysis of the users’ similarity in OSNs is attracting the attention of researchers because of its implications on privacy and social marketing. In particular, the homophily between users could be used to reveal important characteristics that users would like to keep hidden, hence …
Evaluation of Structural and Temporal Properties of Ego Networks for Data Availability in DOSNs
2017
The large diffusion of Online Social Networks (OSNs) has influenced the way people interact with each other. OSNs present several drawbacks, one of the most important is the problem of privacy disclosures. Distributed Online Social Networks (DOSNs) have been proposed as a valid alternative solution to solve this problem. DOSNs are Online Social Networks implemented on a distributed platform, such as a P2P system or a mobile network. However, the decentralization of the control presents several challenges, one of the main ones is guaranteeing data availability without relying on a central server. To this aim, users’ data allocation strategies have to be defined and this requires the knowledg…
Analysis of Users Behaviour from a Movie Preferences Perspective
2018
Despite their tremendous popularity, Online Social Networks (OSNs) have several issues related to the privacy of social users. These issues have motivated researchers to develop OSN services that take advantage of the decentralized platforms (such as P2P systems or opportunistic networks). Decentralized Online Social Networks (DOSNs) need specific approaches to manage the decentralization of social data. In particular, data availability is one of the main issues and current proposals exploit properties of the social relationships to manage it. At the best of our knowledge, there are no proposals which exploit similarity between users, expressed with the term homophily. Homophily has been we…
Evaluating the impact of friends in predicting user’s availability in online social networks
2017
In recent years, Online Social Networks (OSNs) have changed the way people connect and interact with each other. Indeed, most people have registered an account on some popular OSNs (such as Facebook, or Google+) which is used to access the system at different times of the days, depending on their life and habits. In this context, understanding how users connect to the OSNs is of paramount importance for both the protection of their privacy and the OSN’s provider (or third-party applications) that want to exploit this information. In this paper, we study the task of predicting the availability status (online/offline) of the OSNs’ users by exploiting the availability information of their frie…
The impact of user’s availability on On-line Ego Networks: a Facebook analysis
2016
We have defined and implemented a Facebook application to log a Facebook dataset.We have studied and validated the structural properties of the whole dataset and of the Dunbar ego networks.We have analyzed the interactions of the users.The availability of the users in the Dunbar ego networks have been investigated.Our results reveal the presence of the temporal homophily property in the Dunbar ego networks. Online Social Networks (OSNs) are the most popular applications in todays Internet and they have changed the way people interact with each other. Understanding the structural properties of OSNs and, in particular, how users behave when they connect to OSNs is crucial for designing user-c…
Privacy and temporal aware allocation of data in decentralized online social networks
2017
Distributed Online Social Networks (DOSNs) have recently been proposed to grant users more control over the data they share with the other users. Indeed, in contrast to centralized Online Social Networks (such as Facebook), DOSNs are not based on centralized storage services, because the contents shared by the users are stored on the devices of the users themselves. One of the main challenges in a DOSN comes from guaranteeing availability of the users' contents when the data owner disconnects from the network. In this paper, we focus our attention on data availability by proposing a distributed allocation strategy which takes into account both the privacy policies defined on the contents an…
A privacy-aware framework for decentralized online social networks
2015
Online social networks based on a single service provider suffer several drawbacks, first of all the privacy issues arising from the delegation of user data to a single entity. Distributed online social networks (DOSN) have been recently proposed as an alternative solution allowing users to keep control of their private data. However, the lack of a centralized entity introduces new problems, like the need of defining proper privacy policies for data access and of guaranteeing the availability of user's data when the user disconnects from the social network. This paper introduces a privacy-aware support for DOSN enabling users to define a set of privacy policies which describe who is entitle…
A Survey on Privacy in Decentralized Online Social Networks
2018
Decentralized Online Social Networks (DOSNs) have recently captured the interest of users because of the more control given to them over their shared contents. Indeed, most of the user privacy issues related to the centralized Online Social Network (OSN) services (such as Facebook or Google+) do not apply in the case of DOSNs because of the absence of the centralized service provider. However, these new architectures have motivated researchers to investigate new privacy solutions that allow DOSN’s users to protect their contents by taking into account the decentralized nature of the DOSNs platform. In this survey, we provide a comprehensive overview of the privacy solutions adopted by…
An Analysis of the Internal Organization of Facebook Groups
2019
With the rapid development and growth of online social networks (OSNs), researchers have been pushed forward to improve the knowledge of these complex networks by analyzing several aspects, such as the types of social media, the structural properties of the network, or the interaction patterns among users. In particular, a relevant effort has been devoted to the study and identification of cohesive groups of users in OSNs (also referred as communities) because they are the basic building block of each OSN. While several research works on groups in OSNs have mainly focused on identifying the types of groups and the contents created by their members, the analysis of internal organizations of …
DiDuSoNet: A P2P architecture for Ditributed Dunbar-based Social Networks,
2015
Online Social Networks (OSNs) are becoming more and more popular on the Web. Distributed Online Social Networks (DOSNs) are OSNs which do not exploit a central server for storing users data and enable users to have more control on their profile content, ensuring a higher level of privacy. In a DOSN there are some technical challenges to face. One of the most important challenges is the data availability problem when a user is offline. In this paper we propose DiDuSoNet, a novel P2P Distributed Online Social Network where users can exercise full access control on their data. Our system exploits trust relationships for providing a set of important social services, such as trustness, informati…
Privacy-preserving data allocation in decentralized online social networks
2016
International audience; Distributed Online Social Networks (DOSNs) have been recently proposed as an alternative to centralized solutions to allow a major control of the users over their own data. Since there is no centralized service provider which decides the term of service, the DOSNs infrastructure exploits users’ devices to take on the online social network services. In this paper, we propose a data allocation strategy for DOSNs which exploits the privacy policies of the users to increase the availability of the users’ contents without diverging from their privacy preferences. A set of replicas of the profile’s content of a user U are stored on the devices of other users who are entitl…
A data aggregation strategy based on wavelet for the internet of things
2017
The advent of emerging information and communication technologies, such as RFID, small size sensors and sensor networks, has made accessible a huge amount of information that requires sophisticated and efficient search algorithms to support queries on that data. In this paper we focus on the problem of aggregating data collected from these devices to efficiently support queries, inferences or statistics on them. In general, data aggregation techniques are necessary to efficiently collect information in a compact and cost-effective way. Some current solutions try to meet the above criteria, by exploiting different data aggregation techniques, for instance BitVector or Q_Digest. In this manus…
Effective use of educational and vocational guidance services in distance education : the experience of USGM, Italy
2009
Efficient educational and vocational guidance services are more and more necessary to guide young students and professionals to the choice of suitable learning paths. In the distance education context, guidance and counselling services play a crucial role in the students course selection as well as in the management of studies and in the reduction of the drop out rate. This paper describes the experience of the Università degli Studi “Guglielmo Marconi” in the study and research of effective guidance services able to fulfil the needs of different kind of users. Starting from a very heterogeneous student target, USGM guidance project has been conceived to increase the number of people experi…