Computer security


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Learning Area 1 : ICT in Society - Computer Security

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Computer security

  2. 2. Computer Security <ul><li>Computer Security means protecting our computer system and the information they contain against unwanted access, damage, destruction or modification </li></ul><ul><li>Type of security </li></ul><ul><ul><li>Hardware security </li></ul></ul><ul><ul><ul><li>PC-lock, keyboard-locks, smart cards, biometric devices </li></ul></ul></ul><ul><ul><li>Software security </li></ul></ul><ul><ul><ul><li>Activation code, serial number </li></ul></ul></ul><ul><ul><li>Network security </li></ul></ul><ul><ul><ul><li>Firewall </li></ul></ul></ul>
  3. 3. Computer Threats (ancaman) <ul><li>Malicious Code </li></ul><ul><li>Hacker </li></ul><ul><li>Natural Threats </li></ul><ul><li>Theft </li></ul>
  4. 4. Malicious Code <ul><li>Malicious code is a computer program that perform unauthorised processes on a computer or network. </li></ul><ul><li>Various kind of Malicious code: </li></ul><ul><ul><li>Virus </li></ul></ul><ul><ul><li>Trojan Horse </li></ul></ul><ul><ul><li>Logic Bomb </li></ul></ul><ul><ul><li>Trapdoor or Backdoor </li></ul></ul><ul><ul><li>Worm </li></ul></ul>
  5. 5. Malicious Code Malicious Code Explanation Virus <ul><li>A program that can pass on the malicious code to other program by modifying them. </li></ul><ul><li>It attaches itself to the program, usually files with .doc, .xls, .exe extensions </li></ul><ul><li>It destroy or co-exist with the program </li></ul><ul><li>It can overtake the entire computing system and spread to other systems. </li></ul>Trojan Horse <ul><li>A program that perform useful and unexpected action </li></ul><ul><li>It must be installed by users or intruders before it can affect the system’s assets </li></ul><ul><li>Example : login script that requests users’ login ID or password </li></ul><ul><li>The information is then used for malicious purpose </li></ul>
  6. 6. Malicious Code Primary differences between Worm and Virus Malicious Code Explanation Logic Bomb <ul><li>A malicious code that goes off when a specific condition occurs </li></ul><ul><li>Example : Time bomb </li></ul><ul><li>It goes off and causes threats at a specified time or date. </li></ul>Trapdoor/ Backdoor <ul><li>A feature in a program that allows someone to access the program with special privilleges </li></ul>Worm <ul><li>A program that copies and spreads itself through a network </li></ul>Worm Virus Operates through the network Spreads through any medium Spread copies of itself as a stand alone program Spread copies of itself as a program that attaches to other program
  7. 7. Malicious code <ul><li>A computer infected by a virus, worm, or Trojan horse often has the following symptoms: </li></ul><ul><ul><li>Screen displays unusual message or image </li></ul></ul><ul><ul><li>Music or unusual sound plays randomly </li></ul></ul><ul><ul><li>Available memory is less than expected </li></ul></ul><ul><ul><li>Existing programs and files disappear </li></ul></ul><ul><ul><li>Files become corrupted </li></ul></ul>
  8. 8. Hacking <ul><li>Hacking refer to unauthorized access to the computer system by a hacker. </li></ul><ul><li>A hacker is a person who accesses a computer or network illegally. (penceroboh) </li></ul><ul><li>A hacker has advanced computer and network skills. They may use a modem or cable to hack targeted computers. </li></ul>
  9. 9. Nature Threats <ul><li>Computer are also threatened by natural or environmental disaster. </li></ul><ul><li>Examples : </li></ul><ul><ul><li>Flood </li></ul></ul><ul><ul><li>Fire </li></ul></ul><ul><ul><li>Earthquakes, storms, tornados </li></ul></ul><ul><ul><li>Excessive heat </li></ul></ul><ul><ul><li>Inadequate power supply. </li></ul></ul>
  10. 10. Theft <ul><li>Two type of computer theft </li></ul><ul><ul><li>Computer is used to steal money, goods, information and resources. </li></ul></ul><ul><ul><li>Stealing a computers especially notebook and PDA. </li></ul></ul><ul><li>Three approaches to prevent theft </li></ul><ul><ul><li>Prevent access by using locks, smart card or password </li></ul></ul><ul><ul><li>Prevent portability by restricting the hardware from being moved </li></ul></ul><ul><ul><li>Detect and guard all exits and record any hardware. </li></ul></ul>
  11. 11. Security Measures <ul><li>Security Measure </li></ul><ul><ul><li>The precautionary measure taken toward possible danger or damage. </li></ul></ul><ul><li>Six types of security measure </li></ul><ul><ul><li>Data Backup </li></ul></ul><ul><ul><li>Cryptography </li></ul></ul><ul><ul><li>Antivirus </li></ul></ul><ul><ul><li>Anti-spyware </li></ul></ul><ul><ul><li>Firewall </li></ul></ul><ul><ul><li>Human Aspect </li></ul></ul>
  12. 12. Anti-virus <ul><li>A utility program that we use to protect a computer against viruses by identifying and removing computer viruses found in the computer memory, computer storage on incoming e-mail files. </li></ul><ul><li>Example of anti-virus </li></ul><ul><ul><li>Norton Antivirus, AVG, Kaspersky, Bitdefender, Nod32. </li></ul></ul>
  13. 13. Anti-spyware <ul><li>A utility program that we use to protect the computers from spyware </li></ul><ul><li>Spyware is a program placed on a computer without the user’s knowledge. It secretly collect information about the user. </li></ul><ul><li>Spyware usually enter your system through the internet. </li></ul><ul><li>Example of anti-spyware </li></ul><ul><ul><li>Spybot Search and Destroy </li></ul></ul><ul><ul><li>Ad-aware </li></ul></ul><ul><ul><li>Spyware Blaster </li></ul></ul>
  14. 14. Firewall <ul><li>A piece of hardware or software which functions in a networked environment to prevent some communication forbidden by security policy. </li></ul><ul><li>We use firewall to prevent hacking . </li></ul><ul><li>Type of firewall </li></ul><ul><ul><li>Screening Routers </li></ul></ul><ul><ul><li>Proxy Gateway </li></ul></ul><ul><ul><li>Guard </li></ul></ul>
  15. 15. Data Backup <ul><li>Data Backup </li></ul><ul><ul><li>Utility program that makes a copy of files that have been saved onto a disk. </li></ul></ul><ul><ul><li>We backup data to : </li></ul></ul><ul><ul><ul><li>ensure that our data can still be used if the original is corrupted </li></ul></ul></ul><ul><ul><ul><li>Prevent our files from malicious program (virus, trojan horse, worm, logic bomb, ext) </li></ul></ul></ul>
  16. 16. cryptography <ul><li>Is a process of hiding information by altering the actual information into different representation. For example , APA can be written as I?X. </li></ul><ul><ul><li>A process of transforming plaintext into ciphertext then back again. </li></ul></ul><ul><li>Encryption is a process of converting plaintext into chipertext. Decryption is the process of converting ciphertext into plaintext. </li></ul><ul><li>An encryption key is a formula that the sender of that data uses to encrypt plaintext. A decryption is a formula that the recipient of that data uses to decrypt chipertext. </li></ul>
  17. 17. cryptography Plaintext ciphertext ciphertext Plaintext encrypt decrypt
  18. 18. Human Aspect <ul><li>Human aspects refer to the user and also the intruder of a computer system </li></ul><ul><li>Human aspect security is the hardest aspects to give protection to. </li></ul><ul><li>The most common problem of human aspect security is the lack of achieving a good information security procedure. </li></ul>