1. G061 - Network Security

2. Learning Objective: explain methods for combating ICT crime and protecting ICT systems

3. Network Security ICT crime often deliberate act of theft –stealing data (whether viewing or taking), –stealing software or equipment. natural disasters and mistakes by humans can also cause data to be lost or equipment to be damaged networked computers are prone to security problems: –hacking (unauthorised access), –viruses, spyware, malware

4. Network Security Preventative measures: Physical Security Logical Security

5. Physical Security lock the computer up –entry measures to get into room/building security guards/CCTV cameras no floppy/CD/DVD drives –prevents copying & theft of data –prevents virus being transferred onto computer system disable USB ports –memory sticks/removable HDD can’t be used

6. Software Security firewalls, backup, encryption, biometric security, software patches & updates, ‘anti-virus’ & anti-spyware software, access rights, auditing, education of users, user IDs, & passwords –methods for ensuring passwords remain effective

7. Firewall network security device –stands between a network and the outside world –can either be hardware and/or software based. –examines data packets moving into and out of the system configured to permit or deny connections –using a set of rules –access is denied if not allowed by the rules –rules set using the organization's security policy configured by the system administrator –checks data sent by users and applications –filters websites users are permitted to visit

8. Backup making copies of current data –in case the originals are lost or corrupted (or stolen) back-up is made to removable storage media –memory stick, portable HDD, CD-R, DVD-R, magnetic tape…. back-up copy is stored off-site –or in different location data can be restored from the back-up if required

9. Encryption What is encryption? the process of disguising messages –so that only the intended recipient can understand them. –encrypted data can only be understood by reversing the encryption process (decryption) data is sent in a scrambled form. –uses a random process set up using a special key value the data is then decoded at receiver –by reversing the encryption process (decryption)

10. Biometric Security technology used to measure some feature of a person –in order to identify them within a security system fingerprint –scans fingerprint, finds identifying unique marks, –matches/does not match to record in system voice recognition retina scans facial recognition DNA

11. Software patches & updates corrects loopholes & bugs in software –stops hackers exploiting them and gaining access must regularly update virus data files –so new viruses can be detected regular security patches to operating systems & applications –to combat security loopholes & bugs

12. Viruses a virus is a piece of software that is designed to: –cause deliberate harm to data stored on a computer –replicate itself so that it transfers to other computers removable media used in an infected system can then carry the virus to another machine programs downloaded from the Internet can also spread a virus.

13. Spyware What?: collects information about a person or organisation –without the user’s knowledge can track a user’s keystrokes –to find out what is being typed, including passwords Why?: can be used to pass information on to advertisers can be used to find out usernames and passwords –used to hack into a user’s bank account

14. Virus & Spyware Protection install anti-virus software on all computers –detects viruses & malware (e.g. spyware) –allows removal of infected code from file –allows deletion of infected files must regularly update virus data files

15. Access Rights data is commercially valuable –could be stolen or damaged/modified may want to restrict access to data –so that no unauthorised changes can be made different users are given different access rights to data legal restrictions on the access to personal data –DPA

16. Levels of Access Noneuser cannot obtain information nor change data Read onlyuser can obtain information but not change the data Read/writeuser can change data as well as obtain information Append onlyuser cannot change existing data but can add new data Fulladministrator/supervisor level - can perform all operations

17. Audit Logs logs are maintained automatically by the system audit logs track: –who did what, –at which workstation, –when it occurred. logs can be used to see which member of staff: –accessed particular files –other resources – web pages.

18. User IDs & Passwords Why? allow access to user areas –stop unauthorised access –protect data to make individual users members of groups –allow access to files based on access rights –allow access to resources – printers, software to be able to monitor use –audit logs to comply with the law –DPA

19. User IDs Effectiveness of user ID maintained by: must be unique –so can be sure who is doing what can be suspended when user is away –e.g. on holiday, leaves the company …. can be linked to resources –an individual machine –software applications –times of use

20. Passwords Effectiveness of password maintained by: 1.Network Manager: –force password change frequently –make minimum length password –make unrecognisable words only (not in dictionary) –must contain numbers and letters (& punctuations) –cannot reuse passwords –3 incorrect password attempts  account is locked 2.User: –not writing password down –make it something others can’t guess – not personal –make sure no one is looking when you type it in