Computer Security

 

COMPUTER SECURITY

Computer security, also known as cybersecurity, refers to the protection of computer systems and networks from theft, damage, unauthorized access, and other forms of cyber threats. It ensures the confidentiality, integrity, and availability of data and information processed, stored, or transmitted by computers and networks.

A. Short Answer Questions:

1. What is computer security? List its types.
- Computer security refers to the protection of computer systems and networks from theft, damage, or unauthorized access. It ensures the confidentiality, integrity, and availability of data. Types of computer security include:
- Network Security
- Information Security
- Endpoint Security
- Application Security
- Cloud Security

2. What is a computer security threat?
- A computer security threat is any potential risk or event that could cause harm to a computer system, leading to loss of data, unauthorized access, or damage to the system. Examples include viruses, malware, phishing attacks, and ransomware.

3. Mention the importance of regular maintenance of hardware.
- Regular maintenance of hardware is important because it helps in preventing unexpected failures, prolongs the lifespan of devices, ensures optimal performance, reduces downtime, and helps in early detection of potential issues.

4. What is a power protection device? List any four power protection devices.
- A power protection device is designed to protect electronic equipment from power surges, outages, and other electrical disturbances. Four power protection devices are:
- Uninterruptible Power Supply (UPS)
- Surge Protector
- Power Conditioner
- Voltage Regulator

5. Why does the computer system need a power protection device?
- A computer system needs a power protection device to safeguard against electrical disturbances like surges, spikes, and outages, which can cause data loss, hardware damage, and system crashes.

6. Why is UPS used in a computer system?
- A UPS (Uninterruptible Power Supply) is used in a computer system to provide backup power during an outage, allowing the system to shut down safely and preventing data loss or hardware damage.

7. How do you keep your computer in good working condition?
- To keep your computer in good working condition:
- Perform regular updates for the operating system and software.
- Use antivirus software and keep it updated.
- Clean out temporary files and unnecessary programs.
- Regularly check and defragment the hard drive.
- Keep the hardware clean and dust-free.
- Back up important data frequently.

8. What is malicious code? List any two examples of it.
- Malicious code is software or code designed to harm, disrupt, or gain unauthorized access to a computer system. Examples include:
- Virus
- Worm
- Trojan Horse
- Ransomware

9. What is a password? Why do we need to apply a password to a file?
- A password is a string of characters used to verify the identity of a user and grant access to a system or file. Applying a password to a file is necessary to prevent unauthorized access, ensuring that only authorized individuals can view or modify the file.

10. What is cryptography?
- Cryptography is the practice and study of techniques for securing communication and data by converting it into a form that can only be read by those who possess the decryption key. It is used to protect information from unauthorized access.

11. What is a data backup? Mention the importance of a backup system.
- A data backup is the process of copying and storing data so that it can be recovered in case of data loss due to system failure, accidental deletion, or other issues. The importance of a backup system lies in ensuring data recovery, minimizing downtime, and protecting against data loss.

12. What type of utility program is Scandisk?
- Scandisk is a utility program used to scan and repair errors on a hard disk, such as bad sectors, lost clusters, and file system inconsistencies.

13. What is encryption and decryption?
- Encryption is the process of converting data into a coded form to prevent unauthorized access. Decryption is the process of converting the encrypted data back into its original form so that it can be understood.

14. What is defragmentation?
- Defragmentation is the process of reorganizing the data on a hard drive so that related files are stored in contiguous sections, reducing the time it takes for the system to access them and improving overall system performance.

B. Long Answer Questions
1. Why do you need to apply computer security measures? Explain in brief.
- Computer security measures are essential to protect sensitive information, ensure the integrity and availability of data, prevent unauthorized access, and protect systems from malicious attacks like viruses, malware, and phishing. These measures help prevent data breaches, financial losses, and damage to the organization’s reputation.

2. What is hardware security? List and explain in brief any four hardware security measures.
- Hardware security involves protecting the physical components of a computer system from theft, damage, and unauthorized access. Four hardware security measures are:
- Physical Locks: Locking devices that prevent unauthorized access to the hardware.
- Cable Locks: Security cables that physically secure the computer to a desk or stationary object.
- Biometric Scanners: Devices that use biological data (e.g., fingerprints) to control access to the computer.
- Secure Enclosures: Protective cases or cabinets that house and protect sensitive hardware.

3. What is data and software security? List any four data and software security measures.
- Data and software security involves protecting digital information and software from unauthorized access, corruption, or theft. Four security measures are:
- Encryption: Securing data by converting it into an unreadable format.
- Firewalls: Software or hardware that blocks unauthorized access to a network.
- Antivirus Software: Programs designed to detect and remove malicious software.
- Regular Software Updates: Keeping software up to date to protect against vulnerabilities.

4. What is a computer virus? List any four symptoms of computer viruses.
- A computer virus is a malicious program that replicates itself and spreads to other computers, causing harm to the system or data. Four symptoms of computer viruses are:
- Slow system performance
- Unexpected pop-up messages
- Files or programs that suddenly disappear
- Frequent system crashes or reboots

5. List any four preventive ways to protect a computer system from computer viruses.
- To protect a computer system from viruses:
- Install and regularly update antivirus software.
- Avoid opening suspicious email attachments or links.
- Regularly update the operating system and software.
- Use a firewall to block unauthorized access.

6. What is a firewall? List any four purposes of using a firewall.
- A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Four purposes of using a firewall are:
- Blocking unauthorized access to a network
- Monitoring network traffic for suspicious activity
- Preventing access to harmful websites
- Establishing a secure connection between internal and external networks

C. Write Technical terms for the followings:
1. Protecting a computer system from being lost or damaged.
- Data Protection

2. A person who steals or deletes data, information, or files intentionally.
- Hacker or Cybercriminal

3. Securing computer hardware from any kind of harm.
- Hardware Security

4. Making an extra copy of data and software.
- Backup

5. A device that protects a computer system from the fluctuation of electric voltage.
- Voltage Regulator

6. A device that provides backup electric power to the computer.
- Uninterruptible Power Supply (UPS)

7. A secret word that provides accessibility to a user to use a file, application, or computer system.
- Password

8. Copy of data and software stored in a secondary storage device.
- Backup Copy

9. A copy of a file or program that is used when the original file is corrupted.
- Backup File

10. A device that reads information on a fingerprint, facial pattern, voice, or eyes of a person.
- Biometric Scanner

11. Making data or information unreadable by an unauthorized person.
- Encryption

12. Converting unreadable text (i.e., cipher text) back to its original form.
- Decryption

13. What is a security barrier that protects a computer system from only external computer security threats?
- Firewall

14. What is a security measure that protects a computer system from internal and external security threats?
- Antivirus Software

D. Write the Full Forms of the following:
FAT     = File Allocation Table
UPS     = Uninterruptible Power Supply
CVT     = Constant Voltage Transformer
SMPS   = Switched-Mode Power Supply
CCTV = Closed-Circuit Television

E. Choose the Correct Answer:
1. The computer security refers to:
- a) Use of antivirus
- b) Securing computer system
- c) Securing hardware
- d) Protecting data
- Correct Answer: b) Securing computer system

2. Which of the following is software security?
- a) Antivirus software
- b) Password
- c) Scandisk
- d) All of them
- Correct Answer: a) Antivirus software

3. Which protects data and application from unauthorized access?
- a) Antivirus software
- b) Password
- c) Scandisk
- d) None of the above
- Correct Answer: b) Password

4. Which is a power protection device?
- a) UPS
- b) Spike guard
- c) Voltage regulator
- d) All of them
- Correct Answer: a) UPS

5. A malware that monitors online activities of a user on a computer and the Internet is:
- a) Ransomware
- b) Spyware
- c) Spam
- d) All of the above
- Correct Answer: b) Spyware

6. ______ is the process of making a duplicate copy of programs or data.
- a) Photocopy
- b) Backup
- c) Password
- d) None of the above
- Correct Answer: b) Backup

7. ______ is the technique used by cybercriminals to steal sensitive credentials of online users.
- a) Phishing
- b) Ransomware
- c) Spyware
- d) None of the above
- Correct Answer: a) Phishing

F. State whether the following sentences are True or False:

1. The power fluctuation and frequent power failure can damage computer hardware.
- True

2. Computer security means protecting the computer from heat, dust, and water.
- False (Computer security primarily refers to protecting data and systems from unauthorized access and cyber threats, not just physical elements like heat, dust, and water.)

3. Regular maintenance helps to detect problems in computer hardware.
- True

4. Dust particles can damage the optical disk of a computer.
- True

5. A stabilizer supplies backup electric power to electronic goods.
- False (A stabilizer regulates voltage, but it does not provide backup power; that’s the role of a UPS.)

6. The password protects files, application programs from being deleted.
- True

7. Dust, fluctuation of electricity, and overheating can damage the hardware of a computer system.
- True

8. A UPS supplies steady voltage and provides unlimited backup electric power to the electric goods.
- False (A UPS supplies steady voltage and provides backup power, but it doesn’t provide unlimited power.)

9. A malicious website is a site that attempts to install malware onto a user's computer.
- True

10. A biometric door locker prevents the authorized person from entering inside a room.
- False (A biometric door locker is designed to allow only authorized persons to enter.)

11. The process of converting non-readable format data into a readable format is known as encryption.
- False (The process described is decryption; encryption is converting readable data into a non-readable format.)

12. A hardware firewall can block the harmful data that comes in from the Internet.
- True