TCP/IP: How It Works and Why It's Vulnerable

The thing that makes the Internet such a viable communications tool is also it's greatest weakness in terms of privacy, security and control. However with certain precautions the Internet can be made safer for surfing and even afford some amount of privacy.

TCP/IP is a set of protocols that the Internet functions on. They operate hand in hand to deliver information from one point on the globe to another (or several others). The same protocols that keep the information flowing smoothly also make it easy for anyone with a little know how to intercept the information and use it for purposes other than was originally intended.

The Internet is what's known as a packet-switched network. Information is broken down into smaller bits called packets and then sent over the Internet where it is reassembled at the destination and forms a complete piece of data. By contrast the telephone is known as a circuit-switched network where people are connected via a direct circuit. While this offers more security it also has it's limits; if too many callers call the same place at the same time someone isn't going to get through.

TCP: Transmission Control Protocol

The TCP breaks down information into smaller bits of data called packets. These packets are then put into IP envelopes with special instructions called headers. These headers tell the Internet routers were the packet is going and the amount of time the packet should be kept before being discarded. They also tell the receiving computer how big it should be, how to reassemble the data and how large each packet should be. This is called a checksum.

Checksums are used to make sure that the data's integrity is maintained through the entire journey from sender to receiver. If the checksum of the IP envelope does not match the checksum of the packet itself the data is corrupt and the receiving computer will send a message to the sender requesting a new copy of the packet.

IP: Internet Protocol