Lesson Notes By Weeks and Term v4 - SHS 1
COMPUTER AND INFORMATION SECURITY
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COMPUTER AND INFORMATION SECURITY
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Ict
Class: SHS 1
Term: 1st Term
Week: 20
Grade code: 1.2.2.LI.3
Strand code: 2
Sub-strand code: 2
Content standard code: 1.2.2.CS.1
Indicator code: 1.2.2.LI.3
Theme: NETWORK SYSTEMS FOR TRANSMI TTING INFORMATION
Subtheme: COMPUTER AND INFORMATION SECURITY
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This lesson focuses on the physical safety and well-being of computer users and the equipment they use. In Ghana, where we often face challenges like intermittent power supply ("dumsor") and have limited resources, protecting our computers from physical damage is not just a matter of convenience but also an economic necessity. Understanding these risks—from electrical hazards in an internet cafe in Madina to poor posture while studying at home in Cape Coast—is the first step to creating a safe and productive environment for using technology.
Introduction to Physical Safety Risks When we talk about computer security, we often think about viruses and hackers. However, the most immediate danger to both you and the computer is often physical. Physical safety risks are dangers in the physical environment that can cause harm to people (injury, discomfort) or damage to the computer hardware.
We can group these risks into three main categories: Electrical Hazards: Risks related to electricity. Ergonomic Hazards: Risks related to body posture and physical stress. Environmental Hazards: Risks related to the immediate surroundings (e.g., heat, dust, liquids). Category 1: Electrical Hazards
These are the most common and dangerous risks in many Ghanaian homes and schools. Overloaded Sockets and Extension Boards: Explanation: This happens when you plug too many high-power devices into a single wall socket or extension board. Think of a wall socket like a single pipe for water. If you try to connect too many big hoses to it, the pressure will be too much, and the pipe might burst. Similarly, an overloaded socket can overheat, melt the plastic, and cause a fire. Ghanaian Example: In a typical student hostel room, you might see one extension board used for a laptop, a phone charger, a small fridge, an electric iron, and a standing fan all at once. This is extremely dangerous and a common cause of fires. The practice of "daisy-chaining"—plugging one extension board into another—is even worse as it concentrates all the electrical load on the first board and the wall socket. Preventive Measure 1 (Best Solution): Increase the number of wall sockets. This should be done by a qualified electrician. It distributes the electrical load safely. Preventive Measure 2 (Immediate Action): Do not use too many extension boards. Use a high-quality extension board with a built-in fuse or circuit breaker, and only plug in a few devices at a time. Never plug high-power items like fridges or irons into the same extension board as your computer. Power Surges and Fluctuations: Explanation: A power surge is a sudden spike in the electrical voltage. In Ghana, this often happens when the power from ECG (Electricity Company of Ghana) goes off and comes back on suddenly ("light off, light on"). This sudden rush of power can fry the sensitive components inside your computer, like the motherboard or power supply unit. Preventive Measure: Use a Surge Protector or a UPS (Uninterruptible Power Supply). A surge protector (often looks like an extension board) is designed to block or absorb the extra voltage during a surge, protecting your devices. A UPS is even better. It has a battery inside that keeps your computer running for a few minutes after the main power goes off. This gives you time to save your work and shut down the computer properly, protecting it from both the sudden outage and the surge when power returns. Poor Cable Management: Explanation: This refers to having messy, tangled, and unorganised cables on the floor or behind the desk. Dangers: Tripping Hazard: Someone can easily trip over the cables, injuring themselves and pulling the equipment off the desk. Damage to Cables: Tangled cables can get bent, pinched, or damaged, leading to exposed wires (shock hazard) or connection problems. Overheating: Bundled cables can trap heat, which is a fire risk. Preventive Measure: Use cable ties, clips, or conduits to neatly bundle cables together and run them along walls or under the desk, out of the way. Category 2: Ergonomic Hazards
Ergonomics is the science of designing the workplace and equipment to be comfortable and efficient for the user. Poor ergonomics can lead to long-term health problems. Poor Posture: Explanation: Slouching in your chair, craning your neck to see the screen, or having your wrists at an awkward angle while typing. This puts strain on your back, neck, and shoulders, leading to pain and conditions like Repetitive Strain Injury (RSI). Preventive Measure (The 90-90-90 Rule): Keep your elbows bent at a 90-degree angle. Keep your hips bent at a 90-degree angle. Keep your knees bent at a 90-degree angle, with your feet flat on the floor or on a footrest. The top of your monitor should be at or slightly below eye level. Eye Strain: Explanation: Staring at a bright screen for too long without blinking can cause tired, dry, and itchy eyes, headaches, and blurred vision. Preventive Measure (The 20-20-20 Rule): Every 20 minutes, look away from the screen at something 20 feet away for at least 20 seconds. This allows your eye muscles to relax. Also, ensure the room has adequate lighting to reduce glare on the screen. Category 3: Environmental Hazards Dust and Dirt: Explanation: Dust can get inside the computer case and clog the cooling fans. When the fans can't spin properly, the components (like the CPU) overheat, which can slow down the computer or cause permanent damage. Preventive Measure: Regularly clean the computer area. Use a soft cloth to wipe the outside of the computer. For the inside, a can of compressed air can be used by a technician to blow out the dust. Liquid Spills: Explanation: Spilling water, Milo, Sobolo, or any liquid on a laptop or keyboard can cause a short circuit, destroying the internal components instantly. Preventive Measure: Keep all drinks and liquids away from the computer desk. If you must have a drink, use a container with a secure lid and place it on a separate, lower surface. Heat and Poor Ventilation: Explanation: Computers generate a lot of heat. If they are placed in a location with no airflow (e.g., in a tight cabinet or against a wall), the heat builds up, leading to overheating. Preventive Measure: Ensure there is enough space around the computer (especially the back and sides of a desktop tower) for air to circulate freely. Do not block the ventilation slots.