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Computer Security

Computer Security is the protection of computer (hardware,software and data) from malicious attacks or accidental damage.

  • It is also known as cyber security or IT security(rarely).

Threats to Computer System​

Anything that has potential to harm computer system.

  • Physical threat: Anything that has potential to cause physical damage:

    • Fire
    • High voltage
    • Theft
    • overheating
    • water or moisture etc.

  • Non-physical threats: Anything with potential to damage data, information or software of a computer system.

    • Malicious codes
    • Unauthorized access.

Non-Physical / Logical Threats

Malicious codes:​

Malicious codes are code or web script designed to create and exploit system vulnerabilities.

  • It includes computer viruses, worms, trojan horses, malicious web scripts etc.

  • Malware or malicious software is developed to harm the computer system in any way.

  • Computer virus : Computer virus is man-made destructive program capable of hiding and replicating.

  • Destructive task includes: (These are also the symptoms of computer virus infection)

    • Degradation of overall performance
    • Running of unwanted programs
    • Deletion or corruption of files
    • Unnecessary messages
    • High memory usage

  • Computer virus can spread due to:

    • Sharing of portable storage device(like pendrive)
    • Downloading files from unreliable sites
    • Opening infected email attachment
    • Using pirated software

  • You can stay protected from computer virus by:

    • Install and update antivirus software
    • Install firewall
    • Scan computer system periodically
    • Keep Operating system updated
    • Stop using pirated software
    • Dont open suspicious email attachments
    • Don't download from untrusted websites

  • Computer worms : Computer worms are malware that uses network to send copies to other PCS, often without user intervention.

  • Trojan horses : Trojan horses are destructive program that pretend to be a useful program for a user. Unlike virus and worm, it doesn't replicate.

  • Spyware : Type of malware that secretly collects and shares information about a computer or network without the user's consent.

  • Adware : Type of malware that displays unwanted advertisements on your computer.

  • Other non-physical(i.e. logical threats):

    • Hacking : Identifying and exploiting weakness to gain unauthorized access.

      • White hat hackers intend to fix identified weakness
      • Black hat hackers intend to exploit identified weakness for their benefit.

    • Phishing: Tricks individuals into providing sensitive information by pretending to be a trustworthy entity.

    • Pharming: Redirects website traffic to fake sites to steal personal information.

    • Keylogger: Records keystrokes to steal passwords and confidential information.

    • Botnets: Networks of infected computers used for DDoS attacks or sending spam.

    • Rootkit: Tools that enable unauthorized control of a computer system without detection.

Information security​

Refers to protection of data and information from unauthorized accesss or alteration while it is being stored or transmitted from one machine to another.

  • Concerns of information security:
    • Confidentiality: Only authorized users should be able to access the data and information.
    • Integrity: Data should be accurate and unaltered.
    • Availability: Data should always be available to authorized users.
    • Non-repudiation: Sender can't deny his involvement in data transmission.

Information security mechanisms:​

  • Identification and Authentication: Making sure the user is who he/she is claiming to be.

    • Password: A secret word or phrase that a user must enter to gain access to a system or service. It should be strong, combining letters, numbers, and special characters to enhance security.

    • Biometric system: Uses unique physical characteristics such as fingerprints, facial recognition, or iris scans to verify the identity of a user.

  • Firewall: A network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between a trusted network and an untrusted network.

  • Cryptography: The practice of securing information by transforming it into an unreadable format, only accessible to those possessing a secret key.

    • Encryption: The process of converting plain text into ciphertext using an algorithm and a key, making it unreadable to unauthorized users.

    • Decryption: The process of converting ciphertext back into plain text using an algorithm and a key, making it readable to authorized users.

  • Antivirus: Software designed to detect, prevent, and remove malware from a computer system. It scans files and programs for known threats and monitors the system for suspicious activity.

  • Backup System: A process of copying and storing data to ensure it can be restored in case of data loss or corruption. Regular backups are essential for data recovery.

  • Updating System Software: Regularly installing updates and patches for the operating system and applications to fix security vulnerabilities, improve performance, and add new features.

Hardware Security​

Refers to the protection of hardware(physical component of computer) from damage.

Hardware Security Mechanisms:​

  • Regular Maintenance: Routine checks and servicing to ensure hardware components are functioning correctly and to prevent potential failures.

  • Insurance: Financial protection against loss or damage to hardware due to unforeseen events like theft, fire, or natural disasters.

  • Security from theft or harm: Measures such as physical locks, security cameras, and restricted access areas to prevent unauthorized access or damage to hardware.

  • Protection from fire: Installation of fire alarms, fire extinguishers, and fire suppression systems to protect hardware from fire damage.

  • Air conditioning: Maintaining optimal temperature and humidity levels to prevent overheating and moisture damage to hardware components.

  • Power protection devices: Devices that protect hardware from power-related issues.

    • Spike guard: Protects hardware from voltage spikes and surges.
    • UPS (Uninterruptible Power Supply): Provides backup power during outages and protects against power fluctuations.
    • Voltguard: Regulates voltage to ensure a stable power supply to hardware.
    • Surge protector: Shields hardware from sudden voltage spikes.
    • Power conditioner: Improves power quality by filtering out noise and regulating voltage.