The Unsorted BBS Collection/thegreatunsorted.tar/thegreatunsorted/texts/term_papers/cpu-safe.esy

Text File | 1993-12-11 | 15KB | 245 lines

    About two hundred years before, the word "computer" started
to appear in the dictionary. Some people even didn't know what is
a computer. However, most of the people today not just knowing
what is a computer, but understand how to use a computer.
    Therefore, computer become more and more popular and
important to  our society. We can use computer everywhere and
they are very useful and helpful to our life. The speed and
accuracy of computer made people felt confident and reliable.
Therefore, many important information or data are saved in the
computer. Such as your diary, the financial situation of a oil
company or some secret intelligence of the military department. A
lot of important information can be found in the memory of
computer. So, people may ask a question: Can we make sure that
the information in the computer is safe and nobody can steal it
from the memory of the computer?
    Physical hazard is one of the causes of destroying the data
in the computer. For example, send a flood of coffee  toward a
personal computer. The hard disk of the computer could be
endangered by the flood of coffee. Besides, human caretaker of
computer system can cause as much as harm as any physical hazard.
For example, a cashier in a bank can transfer some money from one
of his customer's account to his own account. Nonetheless, the
most dangerous thief are not those who work with computer every
day, but youthful amateurs who experiment at night --- the
hackers.
    The term "hacker "may have originated at M.I.T. as students'
jargon for classmates who labored nights in the computer lab. In
the beginning, hackers are not so dangerous at all. They just
stole computer time from the university. However, in the early
1980s, hackers became a group of criminals who steal information
from other peoples' computer.
    For preventing the hackers and other criminals, people need
to set up a good security system to protect the data in the
computer. The most important thing is that we cannot allow those
hackers and criminals entering our computers. It means that we
need to design a lock to lock up all our data or using
identification to verify the identity of someone seeking access
to our computers.
    The most common method to lock up the data is using a
password system. Passwords are a multi-user computer system's
usual first line of defense against hackers. We can use a
combination of alphabetic and number characters to form our own
password. The longer the password, the more possibilities a
hacker's password-guessing program must work through. However it
is difficult to remember a very long passwords. So people will
try to write the password down and it may immediately make it a
security risk. Furthermore, a high speed password-guessing
program can find out a password easily. Therefore, it is not
enough for a computer that just have a password system to protect
its data and memory.
    Besides password system, a computer company may consider
about the security of its information centre. In the past, people
used locks and keys to limit access to secure areas. However,
keys can be stolen or copied easily. Therefore, card-key are
designed to prevent the situation above. Three types of card-keys
are commonly used by banks, computer centers and government
departments. Each of this card-keys can employ an identifying
number or password that is encoded in the card itself, and all
are produced by techniques beyond the reach of the average
computer criminals. One of the three card-key is called watermark
magnetic. It was inspired by the watermarks on paper currency.
The card's magnetic strip have a 12-digit number code and it
cannot be copied. It can store about two thousand bits in the
magnetic strip. The other two cards have the capability of
storing thousands of times of data in the magnetic strip. They
are optical memory cards (OMCs) and Smart cards. Both of them are
always used in the security system of computers.
    However, it is not enough for just using password system and
card-keys to protect the memory in the computer. A computer
system also need to have a restricting program to verify the
identity of the users. Generally, identity can be established by
something a person knows, such as a password or something a
person has, such as a card-key. However, people are often forget
their passwords or lose their keys. A third method must be used.
It is using something a person has --- physical trait of a human
being.
    We can use a new technology called biometric device to
identify the person who wants to use your computer. Biometric
devices are instrument that perform mathematical analyses of
biological characteristics. For example, voices, fingerprint and
geometry of the hand can be used for identification. Nowadays,
many computer centers, bank vaults, military installations and
other sensitive areas have considered to use biometric security
system. It is because the rate of mistaken acceptance of
outsiders and the rejection of authorized insiders is extremely
low.
    Individuality of vocal signature is one kind of biometric
security system. The main point of this system is voice
verification. The voice verifier described here is a
developmental system at American Telephone and Telegraph. Only
one thing that people need to do is repeating a particular phrase
several times. The computer would sample, digitize and store what
you said. After that, it will built up a voice signature and make
allowances for an individual's characteristic variations. The
theory of voice verification is very simple. It is using the
characteristics of a voice: its acoustic strength. To isolate
personal characteristics within these fluctuations, the computer
breaks the sound into its component frequencies and analyzes how
they are distributed. If someone wants to steal some information
from your computer, the person needs to have a same voice as you
and it is impossible.
    Besides using voices for identification, we can use
fingerprint to verify a person's identity because no two
fingerprints are exactly alike. In a fingerprint verification
system, the user places one finger on a glass plate; light
flashes inside the machine, reflects off the fingerprint and is
picked up by an optical scanner. The scanner transmits the
information to the computer for analysis. After that, security
experts can verify the identity of that person by those
information.
    Finally, the last biometric security system is the geometry
of the hand. In that system, the computer system uses a
sophisticated scanning device to record the measurements of each
person's hand. With an overhead light shining down on the hand, a
sensor underneath the plate scans the fingers through the glass
slots, recording light intensity from the fingertips to the
webbing where the fingers join the palm. After passing the
investigation of the computer, people can use the computer or
retrieve data from the computer.
    Although a lot of security system have invented in our
world, they are useless if people always think that stealing
information is not a serious crime. Therefore, people need to pay
more attention on computer crime and fight against those hackers,
instead of using a lot of computer security systems to protect
the computer.
       Why do we need to protect our computers ?
    It is a question which people always ask in 18th century. However,
every person knows the importance and useful of a computer security
system.
     In 19th century, computer become more and more important and
helpful. You can input a large amount of information or data in a small
memory chip of a personal computer. The hard disk of a computer system is
liked a bank. It contained a lot of costly material. Such as your diary,
the financial situation of a trading company or some secret military
information. Therefore, it just like hire some security guards to protect
the bank. A computer security system can use to prevent the outflow of
the information in the national defense industry or the personal diary in
your computer.
    Nevertheless, there is the price that one might expect to pay for
the tool of security: equipment ranging from locks on doors to
computerized gate-keepers that stand watch against hackers, special
software that prevents employees to steal the data from the company's
computer. The bill can range from hundreds of dollars to many millions,
depending on the degree of assurance sought.
    Although it needs to spend a lot of money to create a computer
security system, it worth to make it. It is because the data in a
computer can be easily erased or destroyed by a lot of kind of hazards.
For example, a power supply problem or a fire accident can destroy all
the data in a computer company. In 1987, a computer centre inside the
Pentagon, the US military's sprawling head quarters near Washington, DC.,
a 300-Watt light bulb once was left burning inside a vault where computer
tapes were stored. After a time, the bulb had generated so much heat that
the ceiling began to smelt. When the door was opened, air rushing into
the room brought the fire to life. Before the flames could be
extinguished, they had spread consume three computer systems worth a
total of $6.3 million.
    Besides those accidental hazards, human is a great cause of the
outflows of data from the computer. There have two kind of people can go
in the security system and steal the data from it. One is those trusted
employee who is designed to let in the computer system, such as
programmers, operators or managers. Another kind is those youth amateurs
who experiment at night ----the hackers.
    Let's talk about those trusted workers. They are the groups who can
easily become a criminal directly or indirectly. They may steal the
information in the system and sell it to someone else for a great profit.
In another hand, they may be bribed by someone who want to steal the
data. It is because it may cost a criminal far less in time and money to
bride a disloyal employee to crack the security system.
    Beside those disloyal workers, hacker is also very dangerous. The
term "hacker" is originated at M.I.T. as students' jargon for classmates
who doing computer lab in the night. In the beginning, hackers are not so
dangerous at all. They just stole some hints for the test in the
university. However, in early 1980s, hacker became a group of criminal
who steal information from other commercial companies or government
departments.
       What can we use to protect the computer ?
    We have talked about the reasons of the use of computer security
system. But what kind of tools can we use to protect the computer. The
most common one is a password system. Password are a multi-user computer
system's which usual used for the first line of defense against
intrusion. A password may be any combination of alphabetic and numeric
characters, to maximum lengths set by the e particular system. Most
system can accommodate passwords up to 40 characters. However, a long
passwords can be easily forget. So, people may write it down and it
immediately make a security risk. Some people may use their first name or
a significant word. With a dictionary of 2000 common names, for instance,
a experienced hacker can crack it within ten minutes.
     Besides the password system, card-keys are also commonly used.
Each kind of card-keys can employ an identifying number or password that
is encoded in the card itself, and all are produced by techniques beyond
the reach of the average computer criminal. Three types of card usually
used. They are magnetic watermark, Optical memory card and Smart card.
    However, both of the tools can be easily knew or stole by other
people. Password are often forgotten by the users and card-key can be
copied or stolen. Therefore, we need to have a higher level of computer
security system. Biometric device is the one which have a safer
protection for the computer. It can reduce the probability of the
mistaken acceptance of outsider to extremely low. Biometric devices are
instrument that perform mathematical analyses of biological
characteristics. However, the time required to pass the system should not
be too long. Also, it should not give inconvenience to the user. For
example, the system require people to remove their shoes and socks for
footprint verification.
    Individuality of vocal signature is one kind of biometry security
system. They are still in the experimental stage, reliable computer
systems for voice verification would be useful for both on-site and
remote user identification. The voice verifier described here is invented
by the developmental system at American Telephone and Telegraph.
Enrollment would require the user to repeat a particular phrase several
times. The computer would sample, digitize and store each reading of the
phrase and then, from the data, build a voice signature that would make
allowances for an individual's characteristic variations.
    Another biometric device is a device which can measuring the act of
writing. The device included a biometric pen and a sensor pad. The pen
can converts a signature into a set of three electrical signals by one
pressure sensor and two acceleration sensors. The pressure sensor can
change in the writer's downward pressure on the pen point. The two
acceleration sensor can measure the vertical and horizontal movement.
    The third device which we want to talk about is a device which can
scan the pattern in the eyes. This device is using an infrared beam which
can scan the retina in a circular path. The detector in the eyepiece of
the device can measure the intensity of the light as it is reflected from
different points. Because blood vessels do not absorb and reflect the
same quantities of infrared as the surrounding tissue, the eyepiece
sensor records the vessels as an intricate dark pattern against a lighter
background. The device samples light intensity at 320 points around the
path of the scan , producing a digital profile of the vessel pattern. The
enrollment can take as little as 30 seconds and verification can be even
faster. Therefore, user can pass the system quickly and the system can
reject those hackers accurately.
    The last device that we want to discuss is a device which can map
the intricacies of a fingerprint. In the verification system, the user
places one finger on a glass plate; light flashes inside the machine
,reflect off the fingerprint and is picked up by an optical scanner. The
scanner transmits the information to the computer for analysis.
    Although scientist have invented many kind of computer security
systems, no combination of technologies promises unbreakable security.
Experts in the field agree that someone with sufficient resources can
crack almost any computer defense. Therefore, the most important thing is
the conduct of the people. If everyone in this world have a good conduct
and behavior, there is no need to use any complicated security system to
protect the computer.

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