Security Software I Should Use?
You might need to obtain
some security software: anti-virus, firewall, and file encryption
Use Anti-Virus Programs
Anti-virus programs look
at the contents of each file, searching for specific patterns that
match a profile - called a virus signature - of something known
to be harmful. For each file that matches a signature, the anti-virus
program typically provides several options on how to respond, such
as removing the offending patterns or destroying the file.
When the anti-virus program
vendors learn about a new virus, they provide an updated set of
virus signatures that include that new one. Through features provided
by the updated anti-virus program, your home computer also automatically
learns of this new virus and begins checking each file for it, along
with checking for all the older viruses. However, viruses never
completely fade away. Their signatures remain part of the master
version of all virus signatures.
Use a Firewall Program
On a computer, this security software acts much like a guard when
it looks at network traffic destined for or received from another
computer. The firewall determines if that traffic should continue
on to its destination or be stopped. The firewall guard
is important because it keeps the unwanted out and permits only
appropriate traffic to enter and leave the computer.
To do this job, the firewall has to look at every piece of information
every packet that tries to enter or leave a computer.
Each packet is labeled with where it came from and where it wants
to go. Some packets are allowed to go anywhere while others can
only go to specific places. If the firewall allows the packet to
proceed (being acceptable according to the rules), it moves the
packet on its way to the destination. In most cases, the firewall
records where the packet came from, where its going, and when
it was seen.
The firewall can check whether a given packet should pass, allowing
the computers user to respond to unanticipated network traffic.
Finally, firewalls can filter packets based not only on their point
of origin or destination, but also on their content.
With a firewall, you can control which packets are allowed to enter
your home computer and which are allowed to leave.
Use a File Encryption Program and Access Controls
Think to your home computer security. The problem is to control
access to files and folders. The access control device here is the
access control list or ACL. ACLs define who can perform actions
on a file or folder: reading and writing, for example. ACLs are
equivalent to a locked filing cabinet for paper documents.
Different computer systems provide different types of ACLs. Some
have fine-grained controls while others have virtually none. The
key is to use all the controls that are available on your computer.
On a computer, when access to information cant be limited,
such for an e-commerce transaction over the Internet, that information
is concealed through a mathematical process called encryption with
another security software - Encryption Program. Encryption transforms
information from one form (readable text) to another (encrypted
text). Its intent is to hide information from those who have neither
the transformation method nor the particulars (the decryption keys)
to transform the encrypted text into readable text. The encrypted
text appears to be gibberish and remains so for people who dont
have the scheme and the keys.
Computer-based encryption schemes must also withstand the test of
time. For example, if a credit card encryption scheme needs six
months of computer time to break, the resulting clear text credit
card number is probably still valid and, therefore, useful to an
intruder. In this case, the encryption scheme isnt strong
enough to guard the information for its entire useful lifetime.
So, to guard paper or computer files, you need to limit who has access
to them by using the access control devices, whether filing cabinets
and safes for paper or access control lists for information on a computer
system. For assets whose access cannot be sufficiently limited, you
need to encrypt them strongly enough so that the time it takes to
decrypt them is longer than their useful life.