A very sample technical report on Decentralized social network.

1. Sample Research on
Decentralized Online Social Networks
Supta Richard Philip
supta.philip@gmail.com
December 21, 2012

2. Abstract
Online 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 playing
an important role in our everyday life. In the last decade, the popularity
of online social network has been increasing tremendously.In this paper, so-
cial networking concepts,history of social networks,challenges in centralized
online social networking and as a solution semantic web technology related
decentralized online social networking and it’s related advantages and chal-
lenges will be discussed.
Keywords: Online Social Network, OSN, Decentralized Social Network.
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3. Contents
1 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
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4. Chapter 1
The state of the art
Now 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,eventually
playing an important role in our everyday life. In last 10 years, the popularity
of online social network has been increasing tremendously. There are millions
of people participating in online diffrent social networks such as Facebook,
LinkedIn,Twitter etc. These social networks has an important role providing
personal communication, group discussion, group messaging, professional ac-
tivities such as job search, collaborative work,business promotions and even
advertizing 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 data
and 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 has
many types of challenges such as having information silos and lack of privacy
control to personal information [2]. In order to these issues, most web com-
munity who are using the traditionally centralized social network is trying
to shift towards a decentralized social network structure. [1]
Having a decentralized Social Network, Semantic web technologies tools are
one of the best solution. [1] To understand Social Networking,its challenges
and solution - Decentralization Framework, we have to understand the main
terminology which are given below:
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5. 1.1 Online Social Network Concepts
The Socialization process, sharing information, knowledge is not a new con-
cept in the society. This process involves the transfer of information from
one 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 individual
people and groups, also the links for the relationships. In practice, the links
can encode all kinds of relationships - personal, professional or organizational
relationship. [3] The important thing is that this nodes and connections in
social networking context are increasing everyday as more profiles and doc-
uments are also created.
1.1.1 Definitions and notation
An Online Social Network (OSN) is defined as web 2.0 platform in which
a person can create a profile, connect to other people or groups, view and
traverse network of connections within the system, share resources and in-
formation within the system and also can interact or collaborate with people
of the same system with the use of social applications [5, 6].
In mathematical definition, a social network can be modeled [4] as an
undirected graph G = (V,E), where V contains users and E is the friendship
relation among them. For each user u ∈ V , function f : V→ 2v maps users
to 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 OSN
The first well-known OSN site, SixDegrees.com, was launched in 1997; its
name originates from the six degrees of separation concept. Six degrees of
separation is the concept that any user can be connected to any other user
through a chain of acquaintances that has no more than five intermediaries.
Through SixDegrees.com users could create their profiles, have a list of friends
and contribute information to their community. Although this site attracted
million of users, it could not survive as a result it closed down in the year
2000. The founder of SixDegrees.com believes that it was ahead of its time.
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6. From 2003, we have seen a revolution on OSN, those sites established back
then are among the most popular OSN sites nowadays. This revolution
has brought a dramatic shift on the business, the society, cultural and the
research arena of the WWW [5]. In the bellow figure shows a timeline of the
evolution 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 systems
in terms of activities. The second branch deals with the data model of
OSNs,Since the data model is the way in which data sources are stored in
a system. The third branch, called system model, categorizes the OSNs
regarding the hosting and content distribution of application servers. The
fourth branch is from the point of view of the formation of users’ network
within OSN platforms. The bellow Figure shows OSNs taxonomy.
Figure 1.2: OSN Taxonomy
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7. 1.2.1 Centralized OSN
The data of centralized OSNs are stored entirely within a cluster or data
center, concentrating the data of all their users under a single administrative
domain. Today, most of the OSNs rely on centralized storage and function-
ality. However, centralized OSNs raise concerns regarding the protection of
privacy and the lack of integration between information silos [7].
1.2.2 Decentralized OSN
The data of decentralized OSNs is distributed across multiple administrative
domains [8].Application servers run on desktop machines owned by users as
peer or a single trusted server. The main problem of this approach is that
peers may not be available continuously [7].
1.3 OSN Challenges
Centralized Online Social Network sites have many benefits to the users but
also have some lackings regarding user data privecy concern and lack of
integration between information silos.User information is scattered over dif-
ferent social networks. A single user might register in various different social
networking sites for different purposes and have different relationships. [1]
Another challenge is lack of control for the user on their personal data and
privecy.In the current centralised structure, users do not have the flexibil-
ity to share their personal information or how they are disseminated over
the many different social networks.User data can be used for financial gains
from advertisements [1]. For example, Facebook’s Beacon is an advertise-
ment features that distribute user data to other websites for the purpose of
advertisement [2].
1.4 Decentralization Social Network Technolo-
gies
Semantic Web technology was suggested to transform from centralized OSN
to decentralized OSN. In Semantic Web, the flow of information is enhanced
via machine-processable metadata which data can be shared and reused on
different applications or by various enterprises of community [9].In Seman-
tic Web technology, ontology represents data in standard format(RDF and
WOL), semantic web reasoning techniques can be applied to link and dis-
cover the connection between data.Recently, there are social network sites
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8. that represent their information in semantic web ontology such as FOAF
format [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 describe
information 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 data
in the Social Networks on the Semantic Web by providing concepts and
properties in RDF format.In social network, to describe personal profile and
social information, SIOC is commonly combined with FOAF [1].
1.5 Advantages of decentralizing Online So-
cial Networks
In 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 to
data for any purposes. Secondly, to access users data in a decentralized so-
cial network, users need to be authenticated throughout different servers and
can also login to different social network services by using the same digital
identification [2].These techniques prevent lack of integration between infor-
mation silos and lack of control for the user on their personal data. It also
hold users privecy on their data.
1.6 Challenges and disadvantages of decen-
tralizing Online Social Networks
As decentralizing Online Social Network paradigm is still in research level,
so there are a lot of limitation.The main disadvantage of this approach is
that 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)
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9. infrastructures and services, the main challenges are to create new perspec-
tives and challenges in networking which Overlay Networking, finding better
solution to ensure Privacy and Trust [7].
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10. Bibliography
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