Why Cookies

Why Cookies

cookie (called an Internet or Web cookie) is the term given to describe a type of message that is given to a Web browser by a Web server
The main purpose of a cookie is to identify users and possibly prepare
customized Web pages or to save site login information for you.

When you enter a Web site using
cookies, you may be asked to fill out a form providing personal
information; like your name, e-mail address, and interests. This
information is packaged into a cookie and sent to your Web browser,
which then stores the information for later use. The next time you go to
the same Web site, your browser will send the cookie to the Web server.
The message is sent back to the server each time the browser requests a
page from the server.

A Web server has no memory so the hosted Web site you are visiting
transfers a cookie file of the browser on your computer’s hard disk so
that the Web site can remember who you are and your preferences. This
message exchange allows the Web server to use this information to
present you with customized Web pages. So, for example, instead of
seeing just a generic welcome page you might see a welcome page with
your name on it.

Types of Cookies

session cookie
called a transient cookie, a cookie that is erased when you close the
Web browser. The session cookie is stored in temporary memory and is not
retained after the browser is closed. Session cookies do not collect
information from your computer. They typically will store information in
the form of a session identification that does not personally identify
the user.

persistent cookie 
called a permanent cookie, or a stored cookie, a cookie that is stored
on your hard drive until it expires (persistent cookies are set with
expiration dates) or until you delete the cookie. Persistent cookies are
used to collect identifying information about the user, such as Web
surfing behavior or user preferences for a specific Web site.

What Information Does a Cookie Store?

For the most part a cookie will contain a string of text that
contains information about the browser. To work, a cookie does not need
to know where you are from, it only needs to remember your browser. Some
Web sites do use cookies to store more personal information about you.
However, this can be done only if you yourself have provided the Web
site with that personal information. Legitimate Web sites will encrypt
this personal information stored in the cookie to prevent unauthorized
usage by another party with access to your cookie folder.

Cookies have six parameters that can be passed to them:

  • The name of the cookie.
  • The value of the cookie.
  • The expiration date of the cookie – this determines how long the cookie will remain active in your browser.
  • The
    path the cookie is valid for – this sets the URL path the cookie us
    valid in. Web pages outside of that path cannot use the cookie.
  • The
    domain the cookie is valid for. This makes the cookie accessible to
    pages on any of the servers when a site uses multiple servers in a
  • The need for a secure connection – this indicates that
    the cookie can only be used under a secure server condition, such as a
    site using SSL.

What are Malicious Cookies?

Cookies normally do not compromise security, but there is a growing
trend of malicious cookies. These types of cookies can be used to store
and track your activity online. Cookies that watch your online activity
are called malicious or tracking cookies. These are the bad cookies to
watch for, because they track you and your surfing habits, over time, to
build a profile of your interests. Once that profile contains enough
information there is a good chance that your information can be sold to
an advertising company who then uses this profile information to target
you with interest specific adverts. Many antivirus programs today will flag suspicious spyware or adware cookies when scanning your system for viruses.

Viewing & Removing Cookies

Cookies are stored by the Web browser on your system’s hard drive,
and you can view them to see which Web sites that you visit are
associated with your cookie files.

If using Internet Explorer,
for example you select Tools then choose Internet Options. On the
general tab you will see a section titled Browser History. Click
Settings then choose View Files.

This will open up a Windows Explorer window that lists all your
temporary Internet files, including your cookies. Each cookie will be
identified by a site URL making it easy to determine which cookies you
trust and want to keep and which you don’t recall from visiting a Web
site and would delete.

To change your cookie settings, simply to go back into Tools then
choose Internet Options. On the Privacy tab you will see a slider bar
which you can move to adjust the level at which your browser accepts
cookies. Low for example blocks third-party cookies that do not have a
compact privacy policy and restricts third-party cookies that save
information that can be used to contact you without your consent. Medium
High will do the same but also block first-party cookies that save
information about you. Other privacy options you can choose would be to
accept all cookies or to block all cookies as well.

If you’re using a browser other than Internet Explorer, you can visit
the following cookie pages on each browser Web site to find out how to
manage your cookies when using Firefox, Opera, or Safari.

First and Third-Party Cookies

When choosing a privacy setting in your browser, two terms you will
see are “first-party cookies” and “third-party cookies”. First party
cookies are those cookies that originate from (or be sent to) the Web
site you’re currently viewing. These types of cookies usually will
contain information about your preferences for that particular Web site.
These cookies are usually Third-party cookies originate from (or will
be sent to) a Web site that is not the site you are visiting. For
example, if the Web site you are on using third-party advertising those
third-party advertising Web sites may use a cookie to track your Web
habits for marketing purposes.

While some may simply choose to block all cookies, it can make Web
surfing difficult if you do this. For example if you shop online, many
e-commerce shopping carts that have been implemented with cookies will
not work. Sites you frequently visit which enable you to personalize
content also will not show your preferences when you visit if you delete
or disable that cookie.

Most cookies, despite some misconceptions, are legitimate files and
will not invade your privacy. Once you get in the habit of reviewing the
cookies associated with your browser and manage them on your own by way
of deleting malicious cookies or trying different browser privacy
settings, you can still keep the good cookies that make surfing a
breeze, yet keep the bad cookies that may be tracking your surfing
habits off your system.

Did You Know…
The name cookie derives from UNIX
objects called magic cookies. These are tokens that are attached to a
user or program and change depending on the areas entered by the user or

Source : Webopedia.com