Zusammenfassung der Ressource
Chapter 7
- ICT Crime
- Physical Methods
- Physical methods - prevent a person
from gaining access to a computer in
person, walking in and sitting at the
computer itself.
- Examples
- Security guards.
- Each employee having a pass which is checked or
used with automated doors.
- Computers in locked room with limited access.
- Screen away from public
in reception areas.
- Logical Methods
- Logical methods - computer-based
methods that can be applied to the
computer by a system administrator.
- Examples
- Usernames
- Unique identifier. Can be allocated to groups.
Restrictions to only logging onto certain machines.
Used to log what each user is doing.
- Passwords
- Method of restricting access.
Not shared with anyone.
- Auditing - overlooking logs. Software can be
used to look at when users start logging
on/off and the data they access.
- Firewalls - A hardware and/or software barrier
between two networks. Used when connecting to
the internet to prevent unauthorised access.
- Encryption - aims to prevent
anyone who has the data
from being able to
understand it without the
appropriate key.
- Networking
- Peer to Peer
- All of the computers
connected to it are of
equal status.
- Any of the computers connected can
provide printer or file-sharing resources.
- Evaluation
- Advantages
- There is no need to purchase an
expensive server. Normal
computers can be used.
- Each user manages
their own computer. This
means that a network
manager is not required.
- Set up is done using wizards. No
technical knowledge is required.
- There is no reliance on a central
server, so the network remains
robust if it fails.
- Disadvanatges
- Each computer is
fulfilling more than one
role – it may be printing or
file sharing. This
increases the load on the
systems.
- The data can be stored
on any computer, so
there is no organisation
to data storage.
- Security, anti-virus protection and
back-ups are the responsibility of
individual users.
- Client-Server
- Powerful controlling
computer: the server.
- Computer controls the
peripherals (printers, back-up,
etc.) and the network security.
- Evaluation
- Advantages
- Back-up, security and
anti-virus protection are
centralised.
- Shared data is
centralised and
organised.
- The user does not do any
of the management of the
computers.
- Network processing is done centrally, not
at individual computers, freeing them to
do what the user wants.
- Disadvantages
- The server and network operating
system cost money.
- A network manager is required.
- There is a reliance on the
central server. If it fails, no
work can be done.
- Stand-Alone
- Not connected to any other computer (i.e.
it is not networked), is said to be
stand-alone.
- Evaluation
- Advantages
- Peripherals such as printers and scanners can be
shared by several workstations reducing the cost.
- Data can be shared. Can allow a
team to work on the same document.
- Access to data is controlled by
usernames, passwords and
associated access rights.
- Back-ups and virus checking can be
controlled from a central location.
- Users can communicate with email
systems and an intranet can
disseminate useful information.
- Disadvantages
- All the services a network provides become unavailable if
the network fails without adequate contingency in place.
- Devices that are required to build the
network depend on the different
topologies.
- If a virus is introduced into a single
workstation, then it can use the
network to spread to the rest.
- If the network is particularly busy, it may
have a detrimental effect on the work
that the user can do.