Distributed Online Social Networks Research Articles

Remote execution of physical tasks by putting into contributionDOSN: Case of Money Transfer

Distributed Online Social Networks (DOSN) provide some advantages that are not yet fully exploited. It can help reduce cost especially when it comes to manage remote physical agents to fulfill some tasks under delegation of other agents that are weakly coupled. This paper tackles the problem of structuring and organizing such a network and a case study is applied on international money transfer. Recent studies showed that the difference between the amounts of money transfer between less developed and developed countries is not too high. The finance institutions for money transfer are widespread but at international level, only few companies share the market giving the lion share to Western Union and Moneygram. Building a social network of “gentlemen” can transform two international transfers to two or more national transfers. It can then reduce the charges of international transfers, speed up at time the process of money transfer, include more people that are outside the banking system. A prototype is constructed using three key concepts to solve arisen problems. Firstly, the gentlemen approach uses some kind of godfather relationship used in most djangui unions in Cameroon to welcome new members. The graph database Neo4J was chosen to ease the process of identifying the chain of godfathers in case a “bad guy” joins and abuse members of the network. Secondly, the knapsack problem in all is varieties is implemented in case the amount to be transferred from one country to another could not match a one-to-one relationship. Thirdly, a signcryption mechanism is used to solve the cryptographic functionalities that occur during message exchanges on the platform. Due to the fact that such social network has to dealt with trust, reputation, privacy and security, it can be considered as a powerful tool for investigating societal problems such as financing terrorism or deception on the Internet. A game theory can then be applied to detect the conditions making the network not interesting to hackers.

Identity-Based Key Management Scheme for Secure Discussion Group Establishment in DOSNs

Distributed online social network (DOSN) solves the challenges of single-point failure and user data privacy faced by traditional online social network (OSN). Online discussion group, allowing a user to facilitate the communications with other users, is one of the most important components of (D)OSN. Key management is the key technology to ensure the secure establishment of discussion groups in DOSNs. However, the existing key management schemes for secure discussion group establishment in DOSNs cannot meet the requirements of sender non-restriction, receiver controllability, round optimal, certificate freeness simultaneously. In this paper, we propose a novel key management scheme for secure discussion group establishment in DOSNs. In our scheme, any user could use our key management scheme to initialize a discussion group with a piece of discussion group information. Users who are interested in the group topic contained in the discussion group information can join and leave the discussion group at any time once the discussion group is initialized with one-round communication. Any user/sender can find the users that he/she wants to communicate with by looking up the discussion group information of a discussion group and then send encrypted messages to some or all of the users in the discussion group. Therefore, our scheme achieves sender non-restriction, receiver controllability, round optimal, certificate freeness simultaneously. Security analysis also shows that our scheme achieves confidentiality, authentication, full collusion resistance, known-key security and perfect forward security.

Notice of Violation of IEEE Publication Principles: Data Trading with a Monopoly Social Network: Outcomes Are Mostly Privacy Welfare Damaging

Notice of Violation of IEEE Publication Principles<br><br> “Data Trading with a Monopoly Social Network: Outcomes are Mostly Privacy Welfare Damaging” <br><br> by Ranjan Pal, Junhui Li, Yixuan Wang, Mingyan Liu, Swades De, and Jon Crowcroft in the IEEE Networking Letters, Volume: 2, Issue: 4, October 2020<br> After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE’s Publication Principles. <br> This paper is a duplication of the original text from the paper cited below. The original text was copied with insufficient attribution and without permission.<br> Due to the nature of this violation, reasonable effort should be made to remove all past references to this paper, and future references should be made to the following article:<br><br> "Too Much Data: Prices and Inefficiencies in Data Markets"<br><br> by Daron Acemoglu, Ali Makhdoumi, Azarakhsh Malekian, and Asuman Ozdaglar NBER Working Paper No. 26296, September 2019<br><br> <br/> This letter argues that data of strategic individuals with heterogeneous privacy valuations in a distributed online social network (e.g., Facebook) will be under-priced, if traded in a monopoly buyer setting, and will lead to diminishing utilitarian welfare. This result, for a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">certain family</i> of online community data trading problems, is in stark contrast to a popular information economics intuition that increased amounts of end-user data signals in a data market improves its efficiency. Our proposed theory paves the way for a future (counter-intuitive) analysis of data trading oligopoly markets for online social networks (OSNs).

A Logical Key Hierarchy Based Approach to Preserve Content Privacy in Decentralized Online Social Networks

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 members ( $n$ n ) of a group, each time a set of users is removed from or added to the group by the group owner. Current solutions fall short in meeting the above criteria, while our approach requires only $O(d\cdot log_d (n))$ O ( d · l o g d ( n ) ) encryption operations when a user is removed from a group (where $d$ d is an input parameter of the system), and $O(2\cdot log_d (n))$ O ( 2 · l o g d ( n ) ) when a user joins the group. The effectiveness of our approach is evaluated through simulations based on a real online social network.

BCOSN: A Blockchain-Based Decentralized Online Social Network

Online social networks (OSNs) are becoming more and more prevalent in people's life, but they face the problem of privacy leakage due to the centralized data management mechanism. The emergence of distributed OSNs (DOSNs) can solve this privacy issue, yet they bring inefficiencies in providing the main functionalities, such as access control and data availability. In this article, in view of the above-mentioned challenges encountered in OSNs and DOSNs, we exploit the emerging blockchain technique to design a new DOSN framework that integrates the advantages of both traditional centralized OSNs and DOSNs. By combining smart contracts, we use the blockchain as a trusted server to provide central control services. Meanwhile, we separate the storage services so that users have complete control over their data. In the experiment, we use real-world data sets to verify the effectiveness of the proposed framework.

SkyEye: A tree-based peer-to-peer monitoring approach

Peer-to-Peer overlays, used by applications like distributed online social networks, need the ability to adjust their system parameters and thus the system performance to provide a certain level of quality, i.e. to ensure maximum response times. For the control of p2p network, a reliable information basis about the system’s state is essential, i.e. what the current average response time is. A precise and rapidly adapting monitoring mechanism can provide the desired knowledge. In this paper we propose SkyEye, a tree-based monitoring approach which operates on top of an existing structured p2p overlay. It provides through a lightweight, error-prone protocol a continuous monitoring of all peers in the network. It gathers and disseminates sophisticated statistics on a wide range of metrics from all peers, to all peers. Evaluation shows a superior precision and adapting rate compared to an implementation of the gossip-based push-sum algorithm in scenarios with churn and without churn.

Evaluation of Structural and Temporal Properties of Ego Networks for Data Availability in DOSNs

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 knowledge of both structural and temporal characteristics of ego networks which is a difficult task due to the lack of real datasets limiting the research in this field. The goal of this paper is the study of the behaviour of users in a real social network in order to define proper strategies to allocate the users’ data on the DOSN nodes. In particular, we present an analysis of the temporal affinity and the structure of communities and their evolution over the time by using a real Facebook dataset.

Information diffusion in distributed OSN: The impact of trusted relationships

Distributed Online Social Networks (DOSN) are a valid alternative to OSN based on peer-to-peer communications. Without centralised data management, DOSN must provide the users with higher level of control over their personal information and privacy. Thus, users may wish to restrict their personal network to a limited set of peers, depending on the level of trust with them. This means that the effective social network (used for information exchange) may be a subset of the complete social network, and may present different structural patterns, which could limit information diffusion. In this paper, we estimate the capability of DOSN to diffuse content based on trust between social peers. To have a realistic representation of a OSN friendship graph, we consider a large-scale Facebook network, from which we estimate the trust level between friends. Then, we consider only social links above a certain threshold of trust, and we analyse the potential capability of the resulting graph to spread information through several structural indices. We test four possible thresholds, coinciding with the definition of personal social circles derived from sociology and anthropology. The results show that limiting the network to “active social contacts” leads to a graph with high network connectivity, where the nodes are still well-connected to each other, thus information can potentially cover a large number of nodes with respect to the original graph. On the other hand, the coverage drops for more restrictive assumptions. Nevertheless the re-insertion of a single excluded friend for each user is sufficient to obtain good coverage (i.e., always higher than 40 %) even in the most restricted graphs. We also analyse the potential capability of the network to spread information (i.e., network spreadability), studying the properties of the social paths between any pairs of users in the graph, which represent the effective channels traversed by information. The value of contact frequency between pairs of users determines a decay of trust along the path (the higher the contact frequency the lower the decay), and a consequent decay in the level of trustworthiness of information traversing the path. We show that selecting the link to re-insert in the network with probability proportional to its level of trust is the best re-insertion strategy, as it leads to the best connectivity/spreadability combination.

DiDuSoNet: A P2P architecture for distributed Dunbar-based social networks

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, information diffusion, and data availability. In this paper we show how our system manages the problem of data availability by proposing a new P2P dynamic trusted storage approach. By following the Dunbar concept, our system stores the data of a user only on a restricted number of friends which have regular contacts with him/her. Differently from other approaches, nodes chosen to keep data replicas are not statically defined but dynamically change according to users churn. In according to our previous work, we use only two online profile replicas at time. By using real Facebook data traces we prove that our approach offers high availability.

A High-Efficiency and High-Accuracy Fully Automatic Collaborative Face Annotation System for Distributed Online Social Networks

The development of fully automatic face annotation techniques in online social networks is currently very important for effective management and organization of a large number of personal photos shared on social network platforms. In this paper, we first propose the personalized hierarchical database access architecture for each member by taking advantage of various social network context types to substantially reduce time consumption. Next, we construct the personalized and adaptive fused face recognition (FR) unit for each member, which uses the AdaBoost algorithm to fuse several different types of base classifiers to produce highly reliable face annotation results. Additionally, to efficiently select suitable personalized face recognizers and then effectively merge multiple personalized face recognizer results, we propose two collaborative FR strategies: the owner with a highest priority rule and using a weighted majority rule for query photos within our collaborative FR framework. The experiment results demonstrate that the evaluation methodologies produced F -measure and Similarity accuracy rates that were, respectively, 64.03% and 63.05% higher for the proposed method in comparison to other state-of-the-art face annotation methods, as well as demonstrating that our method can result in a reduction in overall processing time of 78.06%.

CommonFinder: A decentralized and privacy-preserving common-friend measurement method for the distributed online social networks

Distributed social networks have been proposed as alternatives for offering scalable and privacy-preserving online social communication. Recommending friends in the distributed social networks is an important topic. We propose CommonFinder, a distributed common-friend estimation scheme that estimates the numbers of common-friends between any pairs of users without disclosing the friends’ information. CommonFinder uses privacy-preserving Bloom filters to collect a small number of common-friend samples, and proposes low-dimensional coordinates to estimate the numbers of common friends from each user to any other users. Simulation results on real-world social networks confirm that CommonFinder scales well, converges quickly and is resilient to incomplete measurements and measurement noises.

A Key Issuing Scheme in IBE-based Distributed Online Social Networks

This paper presents a novel key issuing scheme for distributed online social networks based on identity-based encryption (IBE). The scheme involves two essential objects, Key Privacy Authority (KPA) and Privacy Chum (PC). KPA and PC cannot impersonate network users to obtain users’ private keys. The experiment results indicate that the scheme is feasible and efficient, and it can sustain large-scale online social networks.

LotusNet: Tunable privacy for distributed online social network services

The evolution of the role of online social networks in the Web has led to a collision between private, public and commercial spheres that have been inevitably connected together in social networking services since their beginning. The growing awareness on the opaque data management operated by many providers reveals that a privacy-aware service that protects user information from privacy leaks would be very attractive for a consistent portion of users. In order to meet this need we propose LotusNet, a framework for the development of social network services relying on a peer-to-peer paradigm which supports strong user authentication. We tackle the trade-off problem between security, privacy and services in distributed social networks by providing the users the possibility to tune their privacy settings through a very flexible and fine-grained access control system. Moreover, our architecture is provided with a powerful suite of high-level services that greatly facilitates custom application development and mash up.