Information Technology Reference
In-Depth Information
The human immune system continuously defends our bodies by iden-
tifying, immobilizing, and destroying infectious bacteria, fungi, parasites,
and viruses. Some of these infectious agents use new disguises and evolve
new strategies for attack over time. It is a dynamic confrontation similar
to the ones computer systems face with attackers and threats.
The body uses multiple levels of defense within its immune system.
The organs of the immune system are made of lymphoid tissues that are
positioned throughout the body. The lymphatic vessels and lymphatic
nodes are the parts of a special circulatory system. The first line of defense
involves several kinds of physical and chemical barriers. Sweat, tears,
saliva, and mucus are chemical barriers, while the skin and other mem-
brane-lined body passages are physical barriers. The second line of defense
is the inflammatory response — swelling, redness, warmth, and pain in
the area of an infection are common. This is basically due to an increased
blood flow that takes the white blood cells to the infected area. The third
line of defense is the immune response. At this stage, the immune system
is fully active in recognizing, attacking, destroying, and “remembering”
each kind of pathogen or foreign substance that enters the body. This
recognition usually happens through identifying unique proteins that
appear on the invaders' outside surfaces. This stage also involves the
production of antibodies and specialized cells that bind to and inactivate
foreign substances. The variety of antibodies is very large, with different
antibodies destined for different purposes.
The above discussion gives useful ideas for software security systems,
which we now examine:
Not all destruction needs to be immediate. Some antibodies just
coat the foreign invaders with proteins that tag them for the
circulating scavenger (white) cells, which will then engulf and
destroy the intruder. Applications, likewise, can have built-in
generic virus-check capability that tags abnormal activity for a more
detailed analysis and action by other, more powerful virus detection
programs running in the background.
During the infection annihilation process, the body also may
develop a fever. This is usually not because of the virus and the
toxins attacking the body cells. It is an unusual response of the
body intended to make the internal environment less hospitable
to these invaders. This is another important lesson for computer
security; if we cannot destroy the intruder immediately, we can
retard the spread of a virus by creating an environment where the
virus cannot multiply swiftly.
