Date Added: Sep 2010
Computer networks are typically a shared resource used by many applications for many different purposes. Sometimes the data transmitted between application processes is confidential, and the applications would prefer that others be unable to read it. For example, when purchasing a product over the WWW (World Wide Web), users sometimes transmits their credit card numbers over the network. This is a dangerous thing to do since it is easy for a hacker to eavesdrop on the network and read all the packets that fly by. Therefore, users sometimes want to encrypt the messages they send, with the goal of keeping anyone who is eavesdropping on the channel from being able to read the contents of the message.