Networks

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Networks
Presented by Muhammad Shahab Siddiqui PhD (CS)
Student GSESIT, Hamdard University
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• Using Web Services for Trust-based Security in
  Different Networks

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Todays Agenda

• Definition of Network
• Major Types of Networks
• Trust Network
• Social Network
• Computer Network
• Ad-hoc Network

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Definition

• a network is a series of points interconnected by
  some communication medium and have paths.
• Network must have identifier or address to locate
  a point on a path.
• Some procedure or method to be use to communicate
  with different points.

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Definition (contd.)

• by SearchNetworking.com
• In information technology, a network is a
  series of points or nodes interconnected by
  communication paths.
• Networks can interconnect with other networks
  and contain sub-networks.

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Definition (contd.)

• by webopedia.com
• (n.) A group of two or more computer systems
  linked together.
• Computers on a network are called nodes.
  Computers and devices that allocate resources for
  a network are called servers.
• (v.) To connect two or more computers together
  with the ability to communicate with each other.

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Major Types of Networks

• Human Networks
• Business Network
• Entrepreneural Network
• Social Network
• Trust Network
• Alumni Network
• Other Networks
• Transport Network
• Spatial Network

• Technology Networks
• Radio Network
• Television Network
• Electrical Network
• Computer Network
• Telecommunication Network
• Energy Transmission and Distribution Network

From Wikipedia, the free encyclopedia
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Trust Network

• Trust Networks consists of transitive trust
  relationships between people, organizations, and
  software agents connected through a medium of
  communication and interaction. It transforms a
  virtual network.
• Trust between parties within the community can be
  derived by analyzing the trust paths linking the
  parties together.

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Trust Network (contd.)

• Security token services (STS) make trust
  networks scalable by mediating trust between
  companies that would otherwise not be able to
  ascribe trust to another. Rather than maintaining
  pair-wise trust with all potential partners,
  individual companies instead form a trust
  relationship with the STS and then rely on the
  STS to form indirect trust, that is to extend
  trust to another company in which the STS places
  its confidence.

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Trust Network (contd.)

• Trust Transitivity means, for example,
• if Alice trusts Bob who trusts Eric then
• Alice will also trust Eric
• This means that Bob actually tells Alice that he
  trusts Eric, which is called Recommendation.

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Trust Network (contd.)

• But in real life trust is not always transitive,
  for example,
• if Alice trusts Bob to look after her child and
  Bob trusts Eric for fixing his car does not imply
  that
• Alice will also trust Eric to look after her
  child or for fixing her car
• Trust Transitivity collapse because the scopes
  of Alices and Bobs Trust are different.

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Trust Network (contd.)

• Previous examples shows that under certain
  semantic constraints, trust can be transitive and
  a trust system can be used to drive trust.
• Referral Trust (RT) can be based on someones
  recommendation while Functional Trust (FT) based
  on actual trust on someone.

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Trust Network (contd.)

• Functional Trust can be direct or indirect.
• We can derive indirect functional (if) trust by
  extending the trust transitivity to more than
  three persons.
• A --dr? B --dr? C --df? D (eq. 1)
• I-----------------if---------------

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Notation for Trust Network

• arc A, B means that A trusts B
• The symbol used to denote the transitive
  connection of two consecutive arcs to form a
  transitive trust path
• (Alice, Eric) (Alice, Bob Bob, Eric)
• (A,D,if) (A,B,dr B,C,dr C,D,df) for
  eq. 1. Where, if indirect functional trust, dr
  direct referral trust and df direct
  functional trust

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Social Network

• A social network is a social structure made of
  nodes which are generally individuals or
  organizations (profiles). The term was first
  coined in 1954 by J. A. Barnes (in Class and
  Committees in a Norwegian Island Parish, "Human
  Relations"). The maximum size of social networks
  tends to be around 150 people and the average
  size around 124 (Hill and Dunbar, 2002).

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Social Network (contd.)

• An example of a social network diagram

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Social Network (contd.)

• your digital profile is a representation of
  aspects of your self that accretes over time. In
  effect, it is a cumulative digital proxy of you
  that is built from a pre-determined set of
  components. The emergence of this new kind of
  identity representation forces us to think
  differently about 'official' identity than we did
  in pre-digital times.

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Social Network (contd.)

• Traditionally, in an open and democratic
  society, 'documented identity' is meant to be as
  thin as possible. However, in the digital age it
  will be different. Some form of digital
  representation of your identity will exist. It
  will, by its very nature, say more about you than
  your current forms of identification -- which
  have relatively thin information.

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Social Network (contd.)

• To analyze Social Network we use Graph Theory
  and Matrix Algebra.
• Social Scientists use the term Sociograms for
  different graphs directed graph, signed graph,
  bar chart, pie chart, line chart

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Notation of Social Network

• Let N 1, 2, 3, , n denotes a set of nodes,
  which represents the social agents that might be
  tied up in a network of social relationships.
• A network g can be represented by a n x n
  matrix taking on values 0 or 1. That is if gij
  1 then node i is linked to j.
• In a reciprocal relationship, gij gji

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Examples of Social Network

• http//www.myspace.com/
• having Tax information, Music, Videos,
  Horoscopes, Games, Schools, Groups, Comedy,
  Chatrooms, etc.
• http//www.mychlteam.com/
• having schedule, scoreboard, statistics, and
  videos of Central (American) Hockey League

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Examples of Social Network

• http//www.crullzone.com/
• Linking Families in Crull Zone
• http//www.shoutok.com/
• Music Community
• http//www.iVillage.com/
• Every thing related to womens fashion, cooking,
  medical issues, etc.

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Augmented Social Network

• The Augmented Social Network (ASN) was proposed
  in a June 2003 paper presented at the PlaNetwork
  Conference by Ken Jordan, Jan Hauser, and Steven
  Foster. The paper makes the case for a civil
  society vision of digital identity that treats
  Internet users as citizens rather than consumers.

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Augmented Social Network (contd.)

• The Augmented Social Network is a proposal for a
  "next generation" online community that would
  strengthen the collaborative nature of the
  Internet, enhancing its ability to act as a
  public commons that engages citizens in civil
  society. The ASN creates an infrastructure for
  trusted relationships across the entire Internet
  -- enabling innovation in democratic governance,
  alternative economics, and social organization of
  all kinds.

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Augmented Social Network (contd.)

• The ASN is not a piece of software or a website.
  Rather, it is an online community system in the
  public interest that could be implemented in a
  number of ways, using technology that largely
  exists today. The ASN is a system designed to
  help you find others with whom you share
  affinities so you can be introduced to them (in
  an appropriate manner), and then share media with
  them, or form groups based on shared interests.

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Computer Networks

• There are many types of computer networks,
  including
• Local Area Networks (LAN) geographically in same
  building
• Wide Area Networks (WAN) connected by telephone
  lines or radio waves
• Campus Area Network (CAN) limited geographic
  area, such as a campus or military base
• Metropolitan Area Network (MAN) data network for
  a town or city.
• Home Area Network (HAN) within a user's home
  that connects a person's digital devices.

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Computer Networks (contd.)

• There are some other characteristics which extend
  the definition of computer networks, includes
• Topology The geometric arrangement of a computer
  system. Common topologies include a bus, star,
  ring, and mesh.
• Protocol defines a common set of rules and
  signals that computers on the network use to
  communicate. One of the most popular protocols
  for LANs is called Ethernet. Another popular LAN
  protocol is the IBM Token-ring Network.
• Architecture classified as either a
  peer-to-peer or client/server architecture.

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Computer Networks (contd.)
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Computer Networks (contd.)

• A given network can also be characterized by the
  type of data transmission technology in use on it
  (TCP/IP or SNA)
• by whether it carries voice, data, or both kinds
  of signals
• by who can use the network (public or private)
• by the usual nature of its connections (dial-up
  or switched, dedicated or nonswitched, or virtual
  connections)
• and by the types of physical links (for example,
  optical fiber, coaxial cable, and twisted pair).

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Ad Hoc Network

• An ad hoc network is a kind of mobile and
  wireless network without centralized
  administration or fixed network infrastructure,
  in which nodes perform routing discovery and
  routing maintenance in a self-organized way.
  Nodes cooperates with each other in routing and
  other functions.

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Ad Hoc Network (contd.)

• Ad Hoc Networks may contains many peer nodes.
  Each node is a stranger to another. These
  nodes also need trust before they exchange
  information.
• There are two types of trust in this model
  direct trust and recommendation trust.

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Ad Hoc Network (contd.)

• Direct trust means that an entity can trust
  another entity directly using all existing
  experiences it has about that entity.
• Recommendation trust expresses the belief in the
  capability of an entity to decide whether another
  entity is reliable in the given trust class and
  in its honesty when recommending third entities.

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Ad Hoc Network (contd.)

• Ad Hoc Networks mainly used for military,
  emergency and relief scenario, where nonexistence
  of infrastructure do not hinder in establishing a
  network. Nodes creating a virtual set of
  connections between each other.
• Ad Hoc Networks resembles human behavior model
  where people or nodes have never met each other
  communicate with each other on mutual trust
  levels developed over a period of time.

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Conclusion

• We have different networks in existence, which
  have nodes and paths in common, having some
  identifier or address for each node.
• Nodes in a network can exchange information,
  collaborate, and self-organize to benefit the
  users.
• Nodes do not need to know each other but can have
  trust levels between them.

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References

• 1 Simplification and Analysis of Transitive
  Trust Networks, by Audun Jøsang, Elizabeth Gray,
  Michael Kinateder, Web Intelligence and Agent
  Systems, Australia, 2006, http//citeseer.ist.psu.
  edu/746240.html
• 2 Trust Network Analysis with Subjective
  Logic, by Audun Jøsang, Ross Hayward, Simon
  Pope, 29th Australian Computer Science Conference
  (ACSC2006), Tasmania, Australia, Australian
  Computer Society, January 2006,
  http//citeseer.ist.psu.edu/744155.html

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References (contd.)

• 3 http//www.answers.com/topic/social-network
• 4 http//www.answers.com/topic/augmen
  ted-social-network
• 5 http//asn.planetwork.net/index.html
• 6 Social Network Size in Humans, R. A. Hill
  and R. I. M. Dunbar, Human Nature, Vol. 14, No.
  1, pp. 53-72, 2003

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References (contd.)

• 7 Trust Model Based Self-Organized Routing
  Protocol for Secure Ad-hoc Networks, by Xiaoqi
  Li, PhD Term Paper, The Chinese University of
  Hong Kong, April 2003, http//citeseer.ist.psu.edu
  /628444.html
• 8 Trust Networks in a Web Services World, by
  Paul Madsen, May 26, 2004, http//webservices.xml.
  com/pub/a/ ws/2004/05/26/trust.html

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Thanks for Listening

• Special Thanks to
• Dr. Zubair A. Shaikh