Computer Security
Module A02c
Audience and Objectives |
About
this document...
Contents
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Three Aspects of Computer Security
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Hardware Protection
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File Protection
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Summary
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1. The Three Aspects of Computer Security
How can we protect computers and the work we do on them? It can seem like
an overwhelming task. One way to make sense of it all is to look at the
three major aspects of computers and see how we can protect each of them.
They are:
A. Hardware
B. Files
C. Connectivity
In this module, we'll concentrate on hardware and file security. Module
NG06c, Network Security Issues, covers connectivity issues in more detail.
2. Hardware Protection
Some hardware protection measures are needed for any computer; special
measures are often necessary for larger computer systems. When an organization
depends on a computer system for its very existence, a "backup contract"
may be necessary to protect against disasterous loss.
All Computers:
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Temperature
If too high, components malfunction
Components generate heat which must be removed
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Humidity
If too high: condensation and corrosion of metal parts
If too low: static electricity (very high voltage!)
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Electric power
Irregularities: power spikes, dips, and brown-outs
Special care during thunderstorms!
Power failure: Un-interruptible Power Supply (UPS)
Larger Computers:
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Fire
Smoke and ionization detectors, with alarms
Automatic Halon extinguisher system
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Vandalism and sabotage
Lock computers into windowless rooms
Access by card-key or other secure system
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Excess heat
Large computers can get very hot.
Some are even fluid-cooled, like a motor
All large computers require special cooling for the entire room
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Wiring hazards
Because of the many connections made, the number of wires around large
computers can get dangerous
Most computer rooms have raised flooring to allow wires to be easily
pulled between devices, without having people trip over them.
Back to Hardware * To
Main Contents
System Backup Contracts
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A "system backup contract" is like an insurance policy: a contract with
company having a computer system similar to ours
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In case of computer disaster, we can use theirs
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Examples of use:
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San Francisco Earthquake: Bank of America damaged; uses computer in Idaho
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World Trade Center bombing: So many companies need backup that providers
are swamped!
Back to Hardware *
To
Main Contents
3. File Protection
Files on computers contain either programs and data. How they are backed
up depends on the type of system and the type of file.
On All Systems:
Copy original files onto another medium. This is called "making a backup".
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Program files:
Copy or install the original disks to a hard disk
Use the copy and store the originals in a safe place.
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Data files:
Copy the originals to another disk or tape
Put the backup disk or tape in a safe place.
Back to File Protection
* To Main Contents
Microcomputer Backup Systems
Important: keep backups current!
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Diskettes:
For every floppy you own, have a backup copy
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Hard disk: backup on diskettes, tapes, removeable hard disk, or
networked drive
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Diskettes: one for each sub-directory; inexpensive but time-consuming
to do
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Tape cartridge: one for the entire disk; more expensive but can be automated
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Removeable hard drive: most convenient (if you don't have a network)
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Networked drive: save your files on the network server or other computer.
Most convenient if available.
Back to File Protection
* To Main Contents
Access To Networks And Timesharing Systems
Access is restricted to safeguard the computer. Use is allowed only with
user code and password:
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User code:
Like hotel room number
Also gives private access to data files
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Password:
Like hotel room key
All users must enter valid user code and password before doing anything
Back to File Protection
* To Main Contents
Backup on Networks and Timesharing Systems
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Backing file up to tape cartridges is the most common method.
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Backups are performed according to a schedule. For example:
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Weekly: back up all files ("complete" backup); often done on the
weekend or other non-busy time.
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Daily: back up only files that have been changed ("incremental"
backup); often done late at night or during the "wee hours" of the morning
In case of disk disaster:
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Restore all files to week-end condition from the complete backup tape;
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Copy changed files from each daily incremental backup.
Back to File Protection
* To Main Contents
Off-site tape storage:
Many organizations send their backup tapes to a vault in case of fire or
disaster.
Back to File Protection * To
Main Contents
4. Summary
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The "three most important features" of computer security:
Backup, Backup, and Backup!
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Other aspects:
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Electrical power safety, especially during thunderstorms;
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On larger systems: allowing access only to authorized people.
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Related Topics:
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Computer Viruses (module A04c)
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Network Security Issues (module NG06c)
Audience:
This module is for people who are familiar with the overall operation of
computers, and need to know about safeguards for protecting them. These
modules are intended to provide necessary and/or helpful background information:
NG01c:
The Well-Connected Computer;
G11c: Operating Systems;
G06c: Input and Output Overview; G05c:
Primary vs. Secondary Storage; G04c: "Reading" and
"Writing"; G02c: General Computer Organization;
G01c: Fundamental Computer Vocabulary.
Objectives:
Upon successful completion of this module, the student will demonstrate
understanding of:
Generally:
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The measures necessary to insure the security of computer hardware and
files.
Specifically:
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The three-fold nature of computer security: hardware, files, and network;
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The importance of temperature and humidity in safeguarding computer hardware;
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Common methods of protecting against fire on larger computer systems;
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Why access to larger computer hardware is usually restricted;
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Steps that can be taken by large computer owners in case the system is
totally disabled or destroyed;
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The need to restrict access to computers on networked systems;
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The need to back up software and data on any size of system;
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Methods of backing up data on microcomputers;
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Methods of backing up data on larger computers;
About this document...
Module A02c: Computer Security
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Review:
A02cr
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Author:
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Laurence
J. Krieg
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Institution:
- Department
of Computer Information Systems, Washtenaw
Community College
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Date:
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Original: 2 April 1988 (as module C6c)
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Last update: Monday, 31-Aug-2009 11:47:55 EDT