System failure

System failure & wireless security

System Failure

- Is computer security risk-Prolonged malfunction of a computer

Effects

Loss of hardware, software, data and information

Reason• User error• Water / fluid• Dirt / dust• Heat• Cold

• Aging hardware• Natural disaster• Random events• Errors in computer programs• Electrical power variation

And other reasons……

Electrical Disturbance

• Noise• Undervoltage• Overvoltage / Power

surge• Momentary Interruption

Noise

Undervoltage

• Brownout / Sag

• Blackout

Overvoltage / Power Surge

• Surge

• Spike

Momentary Interruption

Safeguards against System Failure

Surge protector

Function of surge protector• Protect electric component from

‘’surgers’’• Protect the computer and other

equipment from large overvoltages and undervoltages.

What actions we can do to Protect our

surge protectors???

metal oxide varistor (MOV)

1.Replacing a surge protector every two

to three years.2.More expensive,

the more protection of the protectors

offers.

How we know the surge protector we purchase is the

best one???Safety specification-Underwritters

Laboratories(UL)1449 standard.The Joule rating of the surge protectors.

(higher joule rating ,the better protection)-review the manufacture’s guarantee

UPS(Uninterrupted Power Supply)

• UPS = Surge protection circuits + 1 or more batteries

• UPS provides power during loss of power

• You connect a UPS between your computer and power source

COMPUTER – UPS – POWER SOURCE

Types of UPS Don’t worry there are only two of them

Standby/Offline

• Switches to battery power when power offline .

• Amount of time to continue using your computer depends on electric requirement of the computer and size of the batteries.

• Less expensive

Online• Always runs off battery• Provides continuous

protection• More expensive

Duplicate Components/ Fault-tolerant Computer

Fault-tolerant computer has duplicate computers so

that it can continue to operate when one of its main components fail

Some Companies have fault-tolerant computers working simultaneously so that their computers are always running.

For example,airline tickets reservation,automated teller machine.

WIRELESS SECURITY

Home user set up wireless home network.

Mobile user access wireless networks in hot sport at airport, hotels, shopping mall and so on.

Although wireless access provides many conveniences, it also posses additional security risk.

WHAT IS WIRELESS SECURITY?

It is the prevention of unauthorized access to computer using wireless networks.

TYPES OF WIRELESS SECURITY

a) WEP (Wireless Equivalent Privacy)• Is one of the least secure form of security

b) WPA (Wi-Fi Protected Access)• Is a quick alternative to improve security

over WEP

TIPS FOR WIRELESS HOME NETWORK SECURITY

1.CHANGE DEFAULT ADMINISTRATOR PASSWORD

•The password provided are simple and very well-known to hackers on Internet

2.TURN ON WPA ENCRYPTION

Encryption technology scrambles messages sent over wireless network , so they cannot easily read by humans.

3.CHANGE THE DEFAULT SSID

Change your network’s SSID to something unique .

4.ENABLE MAC ADDRESS FILTERING With MAC address filtering, you

specify which computers can access your network.

5. DO NOT AUTO-CONNECT TO OPEN WI-FI NETWORKS

6. ASSIGN STATIC IP ADDRESS TO DEVICES

DHCP (Dynamic Host Configuration Protocol)technology

Network attackers can easily obtain valid IP addresses from your network's DHCP pool.

Turn off DHCP on the router or access point, set a fixed IP address range instead, then configure each connected device to match.

Use a private IP address range (like 10.0.0.x)

7. ENABLE FIREWALLS ON EACH COMPUTER AND THE ROUTER

8. POSITION THE ROUTER OR ACCESS POINT SAFELY Wi-Fi signals leakage - easier for others to

detect and exploit. Try to position the access point or router

near the centre of the home rather than near windows -minimize leakage.

9. TURN OFF THE NETWORK DURING EXTENDED PERIOD OF NON-USE

If you own a wireless router but are only using it wired (Ethernet) connections, you can turn off Wi-Fi on a broadband router without powering down the entire network.