What is System Security?
System
security commonly refers to techniques which prevent our computer resources and
data from any unauthorized access. System security covers three major
dimensions of the security which is called CIA ( Confidentiality, Integrity and
Authentication). Confidentiality- ensures protection of the computer system
from any unauthorized access. Integrity- ensures that information stored in the
computer is protected. Authentication- ensures the authenticity of the
authorized user.
Computer Security Threats:
Computer systems are vulnerable to
many threats that can inflict various types of damage resulting in significant
losses. This damage can range from errors harming database integrity to fires
destroying entire computer centers. The effects of various threats vary
considerably. Some affect the confidentiality or integrity of data while others
affect the availability of a system. The following are common threats to the
System security.
Virus : Viruses are computer programs developed to copy
themselves and infect other files stored on the computer. These are malicious
programs that move from computer to computer by attaching themselves to files
or boot records of hard disks. Virus can automatically be transferred from one
computer to another when its host is taken to the target computer, for example
an user can sent it through a network or the internet, or carried it on a
removable storage medium such as CD, DVD, USB pen drive or Memory Cards. These
virus programs can create files, move files, erase files, consume your
computer's memory, and cause your computer not to function correctly. Some
viruses can duplicate themselves, attach themselves to programs, and travel
across networks. In fact opening an infected e-mail attachment is the most
common way to get a virus. Therefore, it is better to prevent an attack than to
try and cure it. There are many antivirus programs available that scan incoming
files for viruses before they can cause damage to your computer. Some of these
programs include Norton Antivirus, McAfee Virus Scan, and Quick Heal.
Worm: A computer worm is a
standalone program made to replicate automatically. A worm replicates
continuously until the entire hard disk space and memory are eaten up and it
may do so without any user intervention. This kind of self replicating programs
spread over the entire hard disk and memory consequently and slow down the
system. Unlike a virus, a worm does not need to attach itself to an existing
executable program or code. Worms harm to a computer or a computer network by
consuming bandwidth and slow down the network speed whereas viruses almost
always corrupt or modify files on a targeted computer.
Trojan Horse:
The
term Trojan is derived from the Trojan Horse story in Greek mythology. Trojan
horse looks like a harmless program but actually performs malicious activities.
The effect of a Trojan could be more dangerous than virus and warms. In fact,
these programs perform some malicious activities like upload (send) some
security files and information from the computer and at the same time download
some unwanted files onto the computer. This way not only it slows own the
network speed but also uploads (sends) some non shareable information to other
computers like our user name, password, emails, credit card details and other
secured information over the network. Trojan horses are designed to allow a
hacker to target a remote computer system. Once a Trojan horse has been
installed on a target computersystem, it is possible for a hacker to access it
remotely and perform various operations and it may do so without any user
intervention at the remote end.
Spyware:
Spyware
is a type of malicious program
installed on computer that collects information about users without their
knowledge. The presence of spyware is typically hidden from the user and can be
difficult to detect. Spyware can capture information like Web browsing habits,
e-mail messages, usernames and passwords, and credit card information. If left
unchecked, the software can transmit this data to another person's computer
over the Internet.
Malware:
All these malicious programs are
termed as “Malware" Malware refers to software programs designed to damage
or do other unwanted actions on a computer system. In Spanish, "mal"
is a prefix that means "bad," making the term "badware,"
which is a good way to remember it (even if you're not Spanish). Common
examples of Malware include viruses, worms, Trojan horses, and Spyware.
Virus detection and its removal: Virus detection and its removal are made through an antivirus program
which finds out viruses in a computer and then possibly removes or repairs the
virus problem. Some of commonly used Virus detection and its removable tools
are Norton Antivirus, McAfee, Virus Scan, Kaspersky and Quick Heal etc. Techniques used for System and Information Security The Techniques used to secure and authorized access of
Computer and Information includes software authorization, authentication,
firewalls, encrypted channels, anti-virus tools and user education. It is a
mechanism through which we can stop entry of viruses and other threats into our
computer system. Some commonly used techniques are-
Username: It is a code
which can be set to log on to a computer access to its resources. Although
setting a username is not mandatory, but it must be set for each user so that
only the authorized ones have the access.
Password: A password is a
secret code or string of characters that is used to authenticate or confirm, to
prove identity or permission to access to a resource. It is used in combination
with the username. It should be kept secret. The password should be strong
enough so that unauthorized used can not guess.
CAPTCHA
(Completely Automated Public Turing Test To Tell Computers and Humans Apart )
The term CAPTCHA was coined in 2000 by Luis
von Ahn, Manuel Blum, Nicholas Hopper and John Langford of Carnegie Mellon
University. A CAPTCHA is a program that protects websites against bots by
generating and grading tests that humans can pass but current computer programs
cannot. For example, humans can read distorted text as the one shown below, but
current computer programs can't:
File Access Permission:
In a
computer network or even in the internet, some files or documents are made
shareable and some are made public. The protected sharable files and documents
are shared among few users or even by agroup having the access rights. Access
rights are generally decided and given by the owner of the file or the network
administrator. Thus the three types of users can access a file or a folder i.e.
Owner, user having access rights, or all other users.
Firewall: A firewall is a
technique used in a secured computer system or network to block unauthorized
access and allow only the authorized user. Firewalls can be implemented in
either hardware or software, or a combination of both. It is a device or set of
devices or software running on a computer, which is configured to permit or
deny computer applications and set of other software based upon a set of rules
and other criteria designed by the network administrator. It also inspects
network traffic passing through it, and denies or permits passage
Digital Certificate: A
digital certificate (also known as a public key certificate or identity
certificate) is an electronic document which uses a digital signature to bind
together a public key or password required for decode and encoded document with
an authentic identity such as the name of a person or an organization, their
phone numbers or address, and so forth. The certificate can be used to verify
that a public key belongs to an authorized individual or organization.
Digital Signature: A
digital signature authenticates electronic documents in a similar manner a
handwritten signature authenticates printed documents. A digital signature is a
method for proving the authenticity of a message or document or attachment or
software sent through email. Digital signatures are commonly used for software
distribution, financial transactions, and in other cases where forgery and
tampering is possible. A valid digital signature gives a recipient enough
reason to believe that the message was created by the known sender, is
completely safe and authentic and that it was not modified. For example, when
sending an e-mail message, you can digitally sign the message by attaching your
digital certificate. Once they receive the message, recipients can verify that
it came from you This protects you from people who might try to
"spoof" an e-mail that looks like it came from you but is really sent
from a different e-mail account
Cookies:
A
cookie (also known as a web cookie, browser cookie, and HTTP cookie) is a small
bit of text or a file that accompanies requests and pages as they go between
the web server and browser. The cookie is sent by a web server to a web browser
and then sent back by the browser each time it accesses that server. Cookies
help web sites to store information about visitors. Some cookies thus may
violate privacy concerns. For example, when a user visits your site, you can
use cookies to store user preferences or other information like password,
address, date of birth etc. When the user visits your web site another time,
the application can retrieve the information it stored earlier. A cookie can
alsobe used for authentication, session tracking (state maintenance), storing
site preferences, shopping cart contents, the identifier for a server based
session, or anything else that can be accomplished through storing textual
data. As text, cookies are not executable. Since they are not executed, they
cannot replicate themselves and not harm the computer directly.
Some
common security measures: Some
Commonly used Preventive Techniques which should be followed by the users are
given below:
ü A computer should be used only by authorized users
[user login].
ü Password should be changed regularly and it should not
be shared to other.
ü Always be careful about some suspicious person who
might see your password while typing.
ü Scan your computer regularly with anti-virus software.
ü Regularly update your antivirus software.
ü Restricted use of removable storage devices,
especially USB Pen Drive.
ü Properly configure the email-filter option to avoid
Spams;
ü Never download any email attachment from an unknown
sender.
ü Must take backup of the computer system regularly.
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