Aaron Dumbeton

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Aaron Dumbeton Scott Goodnack Craig Morgan Mitali
Ray Mark Trusz
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Kinds of Systems

• Distributed Operating Systems

• Network Operating Systems (NOS)

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Distributed Operating Systems
An operating system which connects multiple
computers but appears to the user as if it is
only one computer.
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Network Operating Systems

• Used to set up a LAN (Local Area Network) which
  links multiple personal computers together.
• Allows for sharing or resources and
  communication between the computers.
• User administration
• File sharing
• Printer sharing
• Backing up Data
• Security

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Network Operating Systems
Internet
Intranet
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Internet

• Allows you to connect to and access information
  on countless other networks.
• Cheap and effective way to send and receive data.
  Search other networks for information that has
  been made available.

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Intranet
- An intranet is like a private version of the
internet. - A company can set one up as an
extension of the internet, or it can be confined
to their company.

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RCP

• Stands for Rich Client Protocol
• Used to create Java Programs
• Java is a programming language designed
  specifically to be used with the internet.
• Much easier to use than C.
• allow you to create applications that let you
  interact with a web page.

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Middleware

• - Software which is used to connect two separate
  applications.
• Allows the two applications to request and pass
  data between one another.
• One use of this type of application is connecting
  a web browser to a data base.

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Issues Concerning Distributed Systems
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Issues Concerning Distributed Systems

• Software
• Security

• Transparency
• Scalability

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Transparency

• All pieces of the system should appear as one
• piece.
• All processes should be invisible to the user.

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Scalabilty

• Resources
• Adding Physical Resources
• Adding Software Resources
• Users
• Performance Issues

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Software

• Operating System Kernel
• Open Services
• Distributed Programming Support

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Security

• Data Integrity
• Confidentiality
• System Availability
• User Accountability

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Connections
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• Packets
• Protocol
• Ports
• Endpoint
• Sockets

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• Def- Unit that carries data through the a
  network.
• In a network where routing is performed, the
  router relies on the packet for
• information on its destination.
• Common packets are 1 to 1.5kb and consist of
  three parts
• Header- Stores information on the data being
  carried by the packet.
• Payload- Part of the packet where the data is
  stored.
• Trailer- Contains data to show that the packet
  has been fully read.

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• Def- Protocols are standards in which data,
  transmitted between computers,
• is interpreted.
• Certain protocols are sometimes considered a
  industry standard.
• Examples of commonly used protocols IPv4, IPv6,
  SMTP, HTTP, FTP
• there are hundreds of protocols.
• Protocols are used in software and hardware
  communications.
• Two computers must have the same protocol
  installed in order to
• communicate with each other.

Protocol IPv4
Protocol IPv4
Protocol IPv4
Protocol IPX
?
Data
Data
?
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• Def- A port is a virtual slot in the computer or
  firewall that allows data to
• move in and out of the device.
• Ports serve a important role in security. They
  can be selectively closed
• or opened to control what data can get to your
  computer.
• When a port is created it is given a whole
  number. The number that is
• assigned to the port usually corresponds with
  the type of data that travels
• through it.
• For example, If you want to receive email you
  would open port 25 since
• port 25 is assigned to the Simple mail transfer
  protocol (SMTP).

Port 25 Open
Port 25 Closed
Email
Email
Email
Firewall
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• Def- Any part of a computer or device where there
  is network
• access.
• Endpoints are normally considered to be a IP
  address and
• Port.
• A example is your web browser accessing the
  internet.
• Because it can access the internet through port
  80 and your
• IP it would be considered a endpoint.

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• Def- A socket is a endpoint where the computer
  is listening for a connection.
• Sockets allow for multiple active connections on
  the same port and IP
• address.
• Once a computer initiates a connection it takes a
  listening socket. Now that
• this socket is taken the computer immediately
  creates a new socket that listens
• for the next connection.
• Sockets are normally created by programs that are
  hosting a services which
• other computers access via the network.

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Security Threats
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Security Threats
Computer Security- protection from unauthorized
individuals Security Attack- any action that
results in compromising the security of any form
of information or data.

• Interception
• Interruption
• Modification
• Fabrication

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Interruption
defined as attack on availability availability
- free to provide services
Example denial of services
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Interception
defined as attack on confidentiality confident
iality- information meant to be kept secret
Example eavesdropping
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Modification
defined as attack on integrity integrity-
internal consistency/no corruption
Example Man in the Middle attacks
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Fabrication
defined as attack on authenticity authenticity
- accuracy/reliability
Example spoofing
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Security Mechanisms
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Fundamentals of Security Mechanisms

• There are four different techniques used to
• secure computer networks.
• Encryption sending data in a certain language
  to a
• target. This language is, hopefully, only
  understood by
• the target.
• Authentication verifying that the target is
  indeed who
• or what the target claims to be.
• Authorization The target has been authenticated
  and is
• now given certain rights of communication.
• Auditing the process of collecting and
  assessing a
• business's information systems, practices, and
  operations.

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• Here we have Anna and Suki.
• They are in an online video-chatroom.

Anna wants to talk to Suki
Anna
Suki wants to talk to Anna
Anna can see Suki, she has verified that Suki is
a Japanese woman. (and visa versa) In essence
Suki has passed Annas AUTHENTICATION procedure.
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• Since Anna and Suki met, by chance, on an
  internet forum. Anna will not be telling Suki her
  credit card number or her address and Suki will
  not tell Anna about her fear of clowns.
• Placing these limits, as to what is acceptable
  information to communicate, is called
  AUTHORIZATION.

We trust each other a little bit
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• After, the AUDITING process (or stating what one
  is capable of and their backgrounds. For example,
  Anna knows a little about Japanese culture).
• Luckily, Anna found out that Suki speaks English.
• The two can now communicate.

Hehe, Thanks!
Great hair, Suki!
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• But alas! Sukis friend, and barber, Mei Ling has
  joined the chat as well.

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• Suki wants to talk to Mei Ling without Anna
  knowing what the message is.
• Suki talks to Mei Ling in Japanese.

Anna loves my hair!
Huh?? ????????
Told you, its a great cut! Im studying new
haircuts right now
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Summary

• In essence, what Suki has done is that she has
• ENCRYPTED her message.
• Encryption is taking data, reorganizing the
  data, and
• then sending this data to a target, in the
  hopes that none
• other but the target can understand.
• Suki has encrypted her message very well. Anna
  has no
• idea what Suki said to Mei Ling, because to
  Anna,
• Japanese is indiscernible from random gibberish.

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Fundamentals

• Computer networks operate in much the same way.
• In order for computers to communicate the system
  must
• Authenticate verify the identity of a target
• Authorize give the target certain rights and
  limits
• Encrypt Data send data/messages in such a way
  that only the
• target will understand
• The last criteria, Auditing, is done by humans.
  From a
• business perspective.
• Auditing this is the process of researching a
  businesss practices,
• standards, and perspectives.

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Client-Server Model

• The client-server model consists of two
  components
• The client this element is responsible for
  inquiries.
• The server this element is responsible for
  replies.
• There are two important things to remember.
• The server will never communicate with a client,
  because the
• server only waits for inquiries. The server
  will ignore all data
• unless the server is being addressed directly.
• The client is the initiator and will inquire data
  from the server,
• wait for the information, and then receive the
  information at hand.

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Sources

• Distributed Systems- McGraw Hill, Encyclopedia of
  Science And Technology ,vol.5
• A Security Design for a Wide-Area Distributed
  System- Leiwo, Hanle, Homburg, Gamage, and
  Tanenbaum
• http//computer.howstuffworks.com/question525.htm
• http//compnetworking.about.com/od/itinformationte
  chnology/l/aa083100a.htm
• http//java.sun.com/docs/books/tutorial/networking
  /sockets/
• http//voip.about.com/od/voipbasics/g/protocoldef.
  htm
• http//searchnetworking.techtarget.com/sDefinition
  /0,,sid7_gci212839,00.html
• http//www.watchguard.com/infocenter/editorial/135
  090.asp
• http//citeseerx.ist.psu.edu/leiwo99security
• Interview with Nicholas Chong, Founder and Web
  Developer for Chong Designs, LLC
  (www.chongdesigns.com)