Decentralized social network


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Decentralized social network

  1. 1. Sample Research onDecentralized Online Social Networks Supta Richard Philip December 21, 2012
  2. 2. AbstractOnline Social network has become an important fact of modern society,which is contributing to many aspects of life, like - social, cultural, polit-ical,educational, professional, personal and business life, eventually playingan important role in our everyday life. In the last decade, the popularityof online social network has been increasing tremendously.In this paper, so-cial networking concepts,history of social networks,challenges in centralizedonline social networking and as a solution semantic web technology relateddecentralized online social networking and it’s related advantages and chal-lenges will be discussed.Keywords: Online Social Network, OSN, Decentralized Social Network. i
  3. 3. Contents1 The state of the art 1 1.1 Online Social Network Concepts . . . . . . . . . . . . . . . . . 2 1.1.1 Definitions and notation . . . . . . . . . . . . . . . . . 2 1.2 History of Online Social Networks(OSN) and decentralized OSN 2 1.2.1 Centralized OSN . . . . . . . . . . . . . . . . . . . . . 4 1.2.2 Decentralized OSN . . . . . . . . . . . . . . . . . . . . 4 1.3 OSN Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.4 Decentralization Social Network Technologies . . . . . . . . . 4 1.4.1 Friend-of-a-Friend (FOAF) . . . . . . . . . . . . . . . . 5 1.4.2 Semantically interlinked online communities (SIOC) . . 5 1.5 Advantages of decentralizing Online Social Networks . . . . . 5 1.6 Challenges and disadvantages of decentralizing Online Social Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ii
  4. 4. Chapter 1The state of the artNow a days, Online Social networking has become an important fact of mod-ern society and contributing to life in many contexts,for example social, cul-tural, political, educational, professional, personal and business life,eventuallyplaying an important role in our everyday life. In last 10 years, the popularityof online social network has been increasing tremendously. There are millionsof people participating in online diffrent social networks such as Facebook,LinkedIn,Twitter etc. These social networks has an important role providingpersonal communication, group discussion, group messaging, professional ac-tivities such as job search, collaborative work,business promotions and evenadvertizing government’s programs. The user of this social network are indi-vidual person, company, group or many agencies sharing their information,opinion, knowledge as well as their specific interest. As a result, the dataand information regarding online social networks are increasing every day,so analysis and evaluation of these information are increasing in complex-ity. [1, 2]These current online social networks are isolated and centralized which hasmany types of challenges such as having information silos and lack of privacycontrol to personal information [2]. In order to these issues, most web com-munity who are using the traditionally centralized social network is tryingto shift towards a decentralized social network structure. [1]Having a decentralized Social Network, Semantic web technologies tools areone of the best solution. [1] To understand Social Networking,its challengesand solution - Decentralization Framework, we have to understand the mainterminology which are given below: 1
  5. 5. 1.1 Online Social Network ConceptsThe Socialization process, sharing information, knowledge is not a new con-cept in the society. This process involves the transfer of information fromone individual to another and the information expansion of organizations. [1]Social networks are explicit representations of the relationships between in-dividual user and organizational groups in a community. In the abstract,these networks are just simple undirected graphs with nodes for individualpeople and groups, also the links for the relationships. In practice, the linkscan encode all kinds of relationships - personal, professional or organizationalrelationship. [3] The important thing is that this nodes and connections insocial networking context are increasing everyday as more profiles and doc-uments are also created.1.1.1 Definitions and notationAn Online Social Network (OSN) is defined as web 2.0 platform in whicha person can create a profile, connect to other people or groups, view andtraverse network of connections within the system, share resources and in-formation within the system and also can interact or collaborate with peopleof the same system with the use of social applications [5, 6]. In mathematical definition, a social network can be modeled [4] as anundirected graph G = (V,E), where V contains users and E is the friendshiprelation among them. For each user u ∈ V , function f : V→ 2v maps usersto their set of friends, while f2 maps users to their set of friends of friends: f(u) = { v | (u, v) ∈ E }f2 (u) = { w | w ∈ f(v) ∧ v ∈ f(u) }1.2 History of Online Social Networks(OSN) and decentralized OSNThe first well-known OSN site,, was launched in 1997; itsname originates from the six degrees of separation concept. Six degrees ofseparation is the concept that any user can be connected to any other userthrough a chain of acquaintances that has no more than five intermediaries.Through users could create their profiles, have a list of friendsand contribute information to their community. Although this site attractedmillion of users, it could not survive as a result it closed down in the year2000. The founder of believes that it was ahead of its time. 2
  6. 6. From 2003, we have seen a revolution on OSN, those sites established backthen are among the most popular OSN sites nowadays. This revolutionhas brought a dramatic shift on the business, the society, cultural and theresearch arena of the WWW [5]. In the bellow figure shows a timeline of theevolution of OSN sites during the last decade [7]. Figure 1.1: Timeline of Online Social Network Sites According to G. Pallis [7] the taxonomy of OSN, the key aspect of OSN,is split into four branches. The first branch covers the scope of OSN systemsin terms of activities. The second branch deals with the data model ofOSNs,Since the data model is the way in which data sources are stored ina system. The third branch, called system model, categorizes the OSNsregarding the hosting and content distribution of application servers. Thefourth branch is from the point of view of the formation of users’ networkwithin OSN platforms. The bellow Figure shows OSNs taxonomy. Figure 1.2: OSN Taxonomy 3
  7. 7. 1.2.1 Centralized OSNThe data of centralized OSNs are stored entirely within a cluster or datacenter, concentrating the data of all their users under a single administrativedomain. Today, most of the OSNs rely on centralized storage and function-ality. However, centralized OSNs raise concerns regarding the protection ofprivacy and the lack of integration between information silos [7].1.2.2 Decentralized OSNThe data of decentralized OSNs is distributed across multiple administrativedomains [8].Application servers run on desktop machines owned by users aspeer or a single trusted server. The main problem of this approach is thatpeers may not be available continuously [7].1.3 OSN ChallengesCentralized Online Social Network sites have many benefits to the users butalso have some lackings regarding user data privecy concern and lack ofintegration between information silos.User information is scattered over dif-ferent social networks. A single user might register in various different socialnetworking sites for different purposes and have different relationships. [1]Another challenge is lack of control for the user on their personal data andprivecy.In the current centralised structure, users do not have the flexibil-ity to share their personal information or how they are disseminated overthe many different social networks.User data can be used for financial gainsfrom advertisements [1]. For example, Facebook’s Beacon is an advertise-ment features that distribute user data to other websites for the purpose ofadvertisement [2].1.4 Decentralization Social Network Technolo- giesSemantic Web technology was suggested to transform from centralized OSNto decentralized OSN. In Semantic Web, the flow of information is enhancedvia machine-processable metadata which data can be shared and reused ondifferent applications or by various enterprises of community [9].In Seman-tic Web technology, ontology represents data in standard format(RDF andWOL), semantic web reasoning techniques can be applied to link and dis-cover the connection between data.Recently, there are social network sites 4
  8. 8. that represent their information in semantic web ontology such as FOAFformat [10].1.4.1 Friend-of-a-Friend (FOAF)The FOAF is one of the web semantic technologies which was used to prop-erly define the decentralized social network for connecting social web sites,representational networks and information networks. It is used to describeinformation and activities of people, groups, companies and their relation-ship, across different social networking sites [1].1.4.2 Semantically interlinked online communities (SIOC)Another Semantic Web technology is SIOC. It is used to present rich datain the Social Networks on the Semantic Web by providing concepts andproperties in RDF format.In social network, to describe personal profile andsocial information, SIOC is commonly combined with FOAF [1].1.5 Advantages of decentralizing Online So- cial NetworksIn the Decentralized Social Network, FOAF profile is stored in a public lo-cation or user local machine and any application would be able to access todata for any purposes. Secondly, to access users data in a decentralized so-cial network, users need to be authenticated throughout different servers andcan also login to different social network services by using the same digitalidentification [2].These techniques prevent lack of integration between infor-mation silos and lack of control for the user on their personal data. It alsohold users privecy on their data.1.6 Challenges and disadvantages of decen- tralizing Online Social NetworksAs decentralizing Online Social Network paradigm is still in research level,so there are a lot of limitation.The main disadvantage of this approach isthat peers might not be available continuously if the data is in local ma-chine. Peers are prone to failures, reboots, power-offs and network disconnec-tions [8].Developing efficient Decentralized Online Social Networking (DOSN) 5
  9. 9. infrastructures and services, the main challenges are to create new perspec-tives and challenges in networking which Overlay Networking, finding bettersolution to ensure Privacy and Trust [7]. 6
  10. 10. Bibliography ¨[1] L. Dadkhahan, Wide Review of Social Network and Decentralization¨ , 2012 IACSIT Hong Kong Conferences IPCSIT vol. 30, 2012,IACSIT Press, Singapore.[2] C. A. Yeung, I. Liccardi, K. Lu, O. Seneviratne, T. Berners-Lee, ¨ Decentralization: The future of Online Social Networking¨ W3C Work- , shop on the Future of Social Networking, 2009. ¨[3] T. Finin, L. Ding, L. Zhou, A. Joshi, Social Networking on the Semantic Web¨ Learning Organization: An International Journal, Vol. 12, No.5, , 2005, pp.418-435.[4] G. Mega, A. Montresor,G. P. Picco Ëfficient Dissemination in Decentral- ¨ ized Social NetworksDepartment of Engineering and Information Science (DISI), University of Trento, Italy.[5] Boyd, D., Ellison, N.B.: Social Network Sites: Definition, History, and Scholarship. Journal of Computer-Mediated Communication 13(1), 210- 230 (2008)[6] Datta, A., Buchegger, S., Vu, L.H., Strufe, T., Rzadca, K.: Decentral- ized Online Social Networks. In: Furht, B. (ed.) Handbook of Social Network Technologies and Applications, pp. 349-378. Springer, Heidel- berg (2010).[7] G. Pallis, D. Zeinalipour-Yazti, and M. D. Dikaiakos, Önline Social Net- works: Status and Trends¨ Department of Computer Science, University , of Cyprus,1678, Nicosia, Cyprus.[8] Buchegger, S., Schioberg, D., Vu, L.-H., Datta., A.: PeerSoN: P2P So- cial Networking - Early Experiences and Insights. In: Proceedings of the 2nd Workshop on Social Network Systems (SocialNets 2009), Nurem- berg, Germany (March 2009) 7
  11. 11. [9] L. Zhou, L. Ding, T. Finin, "‘How is the Semantic Web evolving Ady- namic social network perspective"’Computer in Human Behavior, Vol. 27, No. 4, 2011, pp. 1294-1302.[10] J. Golbeck, M. Rothstein, “Linking Social Networks on the Web with FOAF: A Semantic Web Case Study”,Proceedings of the Twenty-Third AAAI Conference on Artificial Intelligence (2008), 2008. 8