Cookies

1
Cookies

• By
• Serdar Torgan
• Emre Chasan Moustafa

2
Outline

• What is a Cookie?
• Typical uses of Cookies
• Cookies and Advertising
• What is wrong?
• Examples
• Conclusion
• References

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What is a Cookie?

• Small piece of information generated by Web
  server and written to your hard-drive for future
  access.
• Provides to store states in Http protocol.
• Uniquely yours and can only be read by the server
  that gave it to you.
• It can not transmit a virus or damage to your
  system.

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Typical uses of Cookies

• User-side customization of Web information
• Start pages.
• Stating that you do not want to see political
  news in a news site.
• Store the ID and password of users in forms of
  Cookies for later access
• Website Tracking
• Develop more efficient pages.
• Discard pages that are not used.
• Personalize search engines.

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Typical uses of Cookies-2

• In commercial applications
• Store shopping lists of items a user has
  selected. Even when you quit and come back later,
  you have the items in your list.
• A tool for tracking browsing and buying habits of
  users.
• Topic causing the most controversy Advertising
  issue

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Setting a Cookie

• GET
  http//www.google.com HTTP/1.1
  Accept /
• HTTP/1.1 200 OK
  Set-Cookie namevalue
  Content-type text/html
• GET
  http//www.google.com HTTP/1.1
• Cookie
  namevalue
• Accept /

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Cookies and Advertising

• By the wide use of commercial applications,
  cookies were utilized for advertising purposes.
• Services like DoubleClick, Focalink, GlobalTrack,
  AdSmart are currently using cookies to develop
  detailed profiles of users and their browsing
  habits.

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Cookies and Advertising-2

• They collect data from users and sell them as
  market information.
• Subscribers to these services put a cookie
  request on their home page.
• When you enter such a site, the cookie is
  requested and the marketing information about you
  is collected from the service.
• Then you receive targetted banners from that site.

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Then what is wrong?

• This is done without anyone's knowledge!
• Not always clear where the cookie is coming from.
• Going on debate if this is a user privacy
  violation or not.

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Cookie attributes

• Besides name/value pair, a cookie also contains
• expiration date when to delete the cookie
• domain name the domain of the server
• path the path in the domain of the server
• Example
• Set-Cookie namevalue expiresdate path/
  domain.domain.com.

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• Examples...

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Conclusion

• Cookies are pieces of information generated by a
  Web server and stored in the user's computer,
  introducing a state to stateless HTTP
  transactions.
• Cookies were intended to be a time-saving device
  for computer users.
• Recently used mostly for advertising and
  collecting marketting information about users
  which is still a hot debate.

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References

• Cookie Central
• http//www.cookiecentral.com/
• The Cookie Controversy
• http//www.cookiecentral.com/ccstory/index.html
• Information About Cookies on Microsoft.com
• http//www.microsoft.com/info/cookies.mspx
• Wikipedia, the free encyclopedia, HTTP Cookie
• http//en.wikipedia.org/wiki/HTTP_cookie

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Any Questions???