IN765 Knowledge Networks
Introductions
Judith Molka-Danielsen
2005
Reference: LINKED by Albert-László
Barábasi
Denial of Service Attacks on the Internet
How vulnerable are we
to such attacks?
BBC News: Thursday, 13 September, 2001, UK
'Mafiaboy' hacker jailed
A Canadian hacker nicknamed Mafiaboy has been sentenced to
eight months in a youth detention centre. Judge Gilles Ouellet
ruled that the 17-year-old teenager from Montreal committed a
criminal act when he crippled major internet sites like Amazon
and Yahoo last year, causing an estimated $1.7 billion in
damages.
Denial-of-service attacks
Mafiaboy admitted involvement in denial-of-service attacks last
year against websites belonging to several companies, including
Amazon, Dell and eBay. The sites were bombarded with
thousands of simultaneous messages, which prevented users
from accessing them for up to five hours. Other charges involved
illegal use of computers to help with the attacks. The judge also
ordered the teenager to face one year of probation after
his detention ends, and fined him $160.
Social Networks and Technology Networks: Paul
spreading the word, he did not walk randomly.
Important features of Networks
• The structure and topology of networks
– Seeing the whole and not just the parts (not
just reductionism).
• The ability to navigate them (search, find).
– Mapping networks – mapping the
interconnectivity – helps us to navigate them.
How are maps useful?
• Maps of the Internet show the points of vulnerability to
hackers
• Maps of organizations of trade and ownership show
trails of power (who affects the outcome of markets).
• Maps of links between species in nature show the
affects of mankind activities on ecosystems.
• Maps of genes in cells show insight into how diseases
grow.
• Surprise: There can be many structural similarities in
these diverse maps. Many networks have common
characteristics of complex networks.
Complex Systems
• Share characteristics of many parts and
many interconnectivities.
• Often in nature these interconnectivities
are not at random; they often follow laws
of self-organization.
Maps of Complex Networks: neurons,
electric power grid, Internet, …
Internet by Bill Cheswick
Neurons by Ricard
New York state power grid
http://complex.upf.es/~ricard/complexnets.html
http://www.math.cornell.edu/~durrett/probrep/probrep.html
http://radio.weblogs.com/0105910/2004/02/16.html
Types of Networks..
Social
Networks
Friends, families,
colleagues
Logical
Networks
Physical
Resources
Web-pages, P2Pfile sharing
Internet IP routers,
circuit switches,
electricity, wireless
telephony
Roads, railroads,
airlines
Transport
Economic
Firms, markets,
organizations
Why Study the Structural
Characteristics of Networks?
• Availability and vulnerability of services: electric,
telephone, air connections, etc.
• Preventing or stopping of viruses on data networks.
• The importance of weak ties: connectivness to the
core, finding a job, finding a web page.
• The characterization (Mapping) of network structure
can lead to a better understanding of
– the role of hubs in the spreading an idea,
– the proliferation of a product in a market, or
– to better management of organizations.
Resources for In765
• The book LINKED is a conversational outline of the basic
concepts of the course. We will use this to guide are
area of study.
• Resources on the web: like NetVis map software,
Java/JUNG, and other visualization systems have to be
explored for your use. I have pointers to some, and you
may find others.
• Some references from our course web page, `Statistical
Mechanics of Complex Networks´ and `Introduction to
Social Network Methods´, contain more details of the
theory and math behind the concepts.
• http://home.himolde.no/~molka/in765/time-plan-05.htm
• You can select a student project that matches your skills
and interests.
Examples of previous projects
Student
Presented Presented Outline – written due
Lecture
17.11.04
Present
Date
Bernt Louis Berge Søvik
Yes
Collaborative Researchers Comparative 24.11 (O)
Tommy Kvalvik
Yes
Internet Routers - IP Adr. -Overload 18.11 (H)
Ronny Hanset Ringen
Yes
Orkut Friends -cluster by country 24.11 (O)
Tor Erik Olsen Smørholm
Yes
Vulnerability and Downtime on Uninett 24.11 (O)
Kristian Kristoffersen
Yes
80-20 Rule 18.11 (H)
Thomas Håseth Johansen
Yes
Information Spread Study 18.11 (H)
Øystein Kaldhol
Yes
BITTORRENT - Lifecycle Analysis ++ 18.11 (H)
Yes
Virus Simulation - Spreading Stopping 24.11 (O)
Yes
Instant Msging - Brass Bands work/play 24.11 (O)
Geir-Arild Hellesvik
Pål Elnan