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Communication Security: Web Based Services • Chapter 5 289

their Web browser of choice (i.e. IE, Firefox, Opera, Netscape, and so forth). If they
suspect something unusual is going on in the background of their system, they can
delete any e-mail they don’t trust, and exit the mail program.This will stop any
Java threads from running in the background. If users are very security conscious,
they might take the safest course and deactivate Java completely. However, with Java
disabled, a user’s Internet experience will probably not be as rich as many Web sites
intended it to be.

ActiveX

ActiveX is Microsoft’s implementation of applets.An ActiveX control is a compo-
nent that functions as a self-sufficient program object that can be downloaded as a
small program or used by other application programs.ActiveX controls are apparent
throughout the modern Windows platform and add many of the new interactive
features of Windows-based applications, and especially Web applications.They also
fit nicely into HTML documents and are therefore portable to many systems, and
can be used in applications to perform repetitive tasks or invoke other ActiveX
controls that perform special functions.
ActiveX controls run in “container” applications, such as the IE Web browser
application or a Visual Basic or Access database application. Once an ActiveX con-
trol is installed, it does not need to be installed again.As a matter of fact, an
ActiveX control can be downloaded from a distant location via a URL link and
run on a local machine over and over without having to be downloaded again. If a
user accesses an HTML document with an ActiveX control, it will check whether
the control is already on the user’s computer. If it is not, it will be downloaded, the
Web page will be displayed, and the ActiveX code will be loaded into memory and
executed.While Java applets are also loaded in the same manner, they are not
installed on a user’s system. Once the user leaves the Web page, a Java applet will
disappear from the system (although it might stay in the cache directory for a lim-
ited time).ActiveX components, however, can be installed temporarily or, more fre-
quently, permanently. One of the most popular ActiveX components is the
Shockwave player by Macromedia. Once installed, it will remain on the user’s hard
drive until you elect to remove it.
Just as programs installed on a Windows platform can be viewed through
add/remove programs in the Control Panel, you can determine what ActiveX con-
trols are installed on your computer through IE.To view, enabled, disable, or delete
ActiveX controls that have been added to IE 7, you can click on the Tools menu,
select Manage Add-ons, and then click the Enable or Disable Add-ons menu

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