2. DATA SECURITY
Data security is about keeping data safe. Many
individuals, small businesses and major
companies rely heavily on their computer
systems
3. KEY THREATS TO DATA
SECURITY
Data may get:
-lost or damaged during a system crash - especially one affecting the hard disk
corrupted as a result of faulty disks, disk drives, or power failures
-lost by accidentally deleting or overwriting files
-lost or become corrupted by computer viruses
-hacked into by unauthorized users and deleted or altered
-destroyed by natural disasters, acts of terrorism, or war
-deleted or altered by employees wishing to make money or take revenge on their employer
4. KEEPING DATA SECURE
Measures that can be taken to keep data
secure include:
-making regular backups of files (backup copies should be stored in
fireproof safes or in another building)
-protecting yourself against viruses by running anti-virus software
-using a system of passwords so that access to data is restricted
-safe storage of important files stored on removable disks, eg locked
away in a fireproof and waterproof safe
5. -allowing only authorised staff into certain computer
areas, eg by controlling entry to these areas by means of
ID cards or magnetic swipe cards
-always logging off or turning terminals off and if possible
locking them
-avoiding accidental deletion of files by write-protecting
disks
-using data encryption techniques to code data so that
itmakes no apparent sense
6. Data Transfer
Transfer of data files containing pictures
(graphics), text, sound, or numbers is possible
from one computer to another, one make of
hardware to another, and one application to
another. This is possible because standard file
types and data formats have been developed.
Data does not need to be transfered on physical
media, it can be transmitted at rapid speeds
around the globe.
7. DATA FILE TYPES
Data files are stored in a number of formats, the formats depend on which
application created the file to begin with.
For example, Microsoft Word stores files as *.doc but Adobe Photoshop stores
files in a different format - *.psd.
The file extension identifies the file's format.
When data is transferred from one computer to another, the computer
receiving the data file may not be able to read the format without the right
application installed.
For example, an image created in Adobe Photoshop and saved as a *.psd file
(Photoshop's format) would not be readable by Microsoft Paint.
8. TRANSLATING BETWEEN
FILE TYPES
Data can be stored temporarily in a computer's RAM as a means of transfer
from one application to another. In Microsoft operating systems this feature is
called the clipboard and it can copy data from one application and paste it into
another. Nearly all other operating systems support this functionality.
For example you can create a graph using a spreadsheet application and then
use the clipboard to copy the graph to a desktop publishing application.
Limitations:
-Certain elements of one document may not be copiable to another
application, eg video.
-Some file features (eg text layout and formatting) may be lost in the
translation to a different format.
9. RAPID TRANSFER OF
DATA
Files can be easily transferred and shared across the
globe using the Internet. A file could be:
emailed as an attachment
sent over instant messenger
downloaded from a website/web server
accessed over a private network
10. IMPORT AND EXPORT
1.Export saves the file in a format that's readable by other applications.
2.Import opens a file created in another application for viewing or
editing.
The need to import and export data files has led to the development
of several standard file types that many applications can
understand.
Examples are jpg and gif files for images, and mp3 files for sound;
but there are also standard file types for text, movies, and
spreadsheet data.
Often an application of a different type can import data, for
example, a word processor may be able to import a spreadsheet file.
11. XML FILES
Recently program developers have started to use the
XML web page file format as the standard way to store
data. Files can be read by any browser on any
computer, making it very easy to transfer data between
computers.
Other standard file types, such as zip and pdf (portable
document format), have been developed as ways of
distributing data in the most efficient way possible. They
do this by compressing it using zip technology or making it
possible to read using a freely available downloaded
reader application, as is the case with PDF files.
