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
Software Security

5. Physical Security lock the computer up security guards/CCTV cameras
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. 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

8. 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
filters websites users are permitted to visit

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
retinal 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 None user cannot obtain information nor change data
Read only
user can obtain information but not change the data
Read/write
user can change data as well as obtain information
Append only
user cannot change existing data but can add new data
Full
administrator/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: 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
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