Network Security

A network, in computing, is a group of two or more devices that can communicate. In practice, a network is comprised of a number of different computer systems connected by physical and/or wireless connections. The scale can range from a single PC sharing out basic peripherals to massive data centers located around the World, to the Internet itself.  Computer networks serve a number of purposes, some of which include:

Communications such as email, instant messaging, chat rooms, etc.

Shared hardware, data and information through the use of shared storage devices

Shared software, which is achieved by running applications on remote computers

Following characteristics are also used to categorize different types of networks:

The geometric arrangement of a computer system. Common topologies include a bus, star, and ring.

The protocol defines a common set of rules and signals that computers on the network use to communicate. One of the most popular protocols for LANs is called Ethernet.

Networks can be broadly classified as using either a peer-to-peer or client/server architecture.

Network security consists of the policies and practices adopted to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources. Network security involves the authorization of access to data in a network, which is controlled by the network administrator. Users choose or are assigned an ID and password or other authenticating information that allows them access to information and programs within their authority. Network security covers a variety of computer networks, both public and private, that are used in everyday jobs; conducting transactions and communications among businesses, government agencies and individuals. Networks can be private, such as within a company, and others which might be open to public access.

Network security starts with authentication, commonly with a username and a password. Since this requires just one detail authenticating the user name—i.e., the password—this is sometimes termed one-factor authentication. With two-factor authentication, something the user ‘has’ is also used (e.g., a security token or ‘dongle’, an ATM card, or a mobile phone); and with three-factor authentication, something the user ‘is’ is also used (e.g., a fingerprint or retinal scan).