lec-1/network security/2019

What Is Network Security?
As we know, computer networks are distributed networks of computers that are either strongly connected meaning that they share a lot of resources from one central computer or loosely connected, meaning that they share only those resources that can make the network work. When we talk about computer network security, It is no longer one computer but a network.
So computer network security is a broader study of computer security. It is still a branch of computer science, but a lot broader than that of computer security.
It involves creating an environment in which a computer network, including all its resources, which are many; all the data in it both in storage and in transit; and all its users are secure. Because it is wider than computer security, this is a more complex field of study involving more de tailed mathematical designs of cryptographic, communication, transport, and exchange protocols and best practices.
Securing the Computer Network
In short, we protect objects. System objects are either real or not real. In a computer network model, the real objects are the hardware resources in the system, and the not real object is the information and data in the system, both in transition and static in storage.
1.Hardware
Protecting hardware resources include protecting :-
• End user objects that include the user interface hardware components such as all client system input components, including a keyboard, mouse, touch screen, light pens, and others.
• Network objects like firewalls, hubs, switches, routers and gateways which are vulnerable to hackers.
• Network communication channels to prevent eavesdroppers from intercepting network communications.
2.Software
Protecting software resources includes protecting hardware-based software, operating systems, server protocols, browsers, application software, and intellectual property ملكية فكرية stored on network storage disks and databases.
It also involves protecting client software such as investment portfolios, financial data, real estate records, images or pictures, and other personal files commonly stored on home and business computers.