The Internet

In order to understand the security issues of the Internet, you first need to understand what the Internet really is. The Internet is not just one network. The Internet includes thousands of individual networks. The communication core of these networks is two protocols known as Transmission Control Protocol and Internet Protocol (TCP/IP) . These historic protocols provide connectivity between equipment from many vendors over a variety of networking technologies. The Transmission Control Protocol (TCP) is intended for use as a highly reliable host-to-host protocol in a packet-switched computer communication network. The Internet Protocol (IP) is specifically limited in scope to provide the functions necessary to deliver an envelope of data from one computer system to another. Each computer or device on a network will have some type of address that identifies where it is on the network.

Much like computers, the Internet is a new concept for the world of communication. In 1973 Vinton Cerf, a UCLA (University of California, Los Angeles) graduate student who is also known as the Father of the Internet, and Robert Kahn, an MIT (Massachusetts Institute of Technology) math professor, developed a set of software protocols to enable different types of computers to exchange data. The software they developed is now known as TCP/IP. The base part of the protocol is called IP or Internet Protocol. While the IP part of the protocol transports the packets of data between the various computer systems on the Internet, the TCP part ports data to the applications. TCP is the mechanism that allows the WWW (World Wide Web) to communicate. (All of this will be discussed in detail later in this book.) Programs are built on top of this medium, which allows communication between server and client. A network can be connected with cables and/or wireless adapters. Basically the computer is connected via a Network Interface Card (NIC) . The NIC card's job is to place data into the network. All network data is crafted into packets and each packet has the information needed to find its target computer and knows where it came from.